DebugInfo: Emit as "C++" rather than "C" (#6361)

This helps at least lldb handle calling functions (currently the debug
info describes every function as `void()`, so no parameters or return
values are supported) - seems gdb and lldb both depend on demangling to
varying degrees in C code (marking a function as "prototyped" in C in
DWARF does seem to also address this problem).

Given:
```
fn PrintThree() {
  Core.Print(3);
}
```
Before:
```
  (lldb) p PrintThree()
  error: Couldn't look up symbols:
    PrintThree
  Hint: The expression tried to call a function that is not present in
    the target, perhaps because it was optimized out by the compiler.
```
After:
```
  (lldb) p PrintThree()
  3
  (lldb)
```

toolchain/driver/testdata/compile/optimize/clang_no_optimize_twice.carbon

@@ -65,7 +65,7 @@ fn Call() -> i32 {
 // CHECK:STDOUT: !2 = !{i32 1, !"wchar_size", i32 4}
 // CHECK:STDOUT: !3 = !{i32 8, !"PIC Level", i32 0}
 // CHECK:STDOUT: !4 = !{i32 7, !"PIE Level", i32 2}
-// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !5 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !6, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !6 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !7 = distinct !DISubprogram(name: "Call", linkageName: "_CCall.Main", scope: null, file: !6, line: 12, type: !8, spFlags: DISPFlagDefinition, unit: !5)
 // CHECK:STDOUT: !8 = !DISubroutineType(types: !9)

toolchain/driver/testdata/compile/optimize/optimize_debug.carbon

@@ -91,7 +91,7 @@ fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/driver/testdata/compile/optimize/optimize_default.carbon

@@ -91,7 +91,7 @@ fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/driver/testdata/compile/optimize/optimize_none.carbon

@@ -113,7 +113,7 @@ fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/driver/testdata/compile/optimize/optimize_size.carbon

@@ -113,7 +113,7 @@ fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/driver/testdata/compile/optimize/optimize_speed.carbon

@@ -107,7 +107,7 @@ fn VectorizedWithOptSpeed(a: array(i32, 65536)*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "foo.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "NoInlineWithOz", linkageName: "_CNoInlineWithOz.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/driver/testdata/stdin.carbon

@@ -76,5 +76,5 @@
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "-", directory: "")

toolchain/lower/context.cpp

@@ -77,12 +77,10 @@ auto Context::BuildDICompileUnit(llvm::StringRef module_name,
                             llvm::DEBUG_METADATA_VERSION);
   // TODO: Include directory path in the compile_unit_file.
   llvm::DIFile* compile_unit_file = di_builder.createFile(module_name, "");
-  // TODO: Introduce a new language code for Carbon. C works well for now since
-  // it's something debuggers will already know/have support for at least.
-  // Probably have to bump to C++ at some point for virtual functions,
-  // templates, etc.
-  return di_builder.createCompileUnit(llvm::dwarf::DW_LANG_C, compile_unit_file,
-                                      "carbon",
+  // TODO: Introduce a new language code for Carbon. C++ works well for now
+  // since it's something debuggers will already know/have support for at least.
+  return di_builder.createCompileUnit(llvm::dwarf::DW_LANG_C_plus_plus,
+                                      compile_unit_file, "carbon",
                                       /*isOptimized=*/false, /*Flags=*/"",
                                       /*RV=*/0);
 }

toolchain/lower/testdata/alias/local.carbon

@@ -40,7 +40,7 @@ fn F() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "local.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/array_in_place.carbon

@@ -44,7 +44,7 @@ fn G() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "array_in_place.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/assign_return_value.carbon

@@ -67,7 +67,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "assign_return_value.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/base.carbon

@@ -88,7 +88,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "base.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/field.carbon

@@ -72,7 +72,7 @@ class A {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "field.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Init", linkageName: "_CInit.A.Main", scope: null, file: !3, line: 16, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/field_addr.carbon

@@ -72,7 +72,7 @@ class A {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "field_addr.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Init", linkageName: "_CInit.A.Main", scope: null, file: !3, line: 16, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/function_param.carbon

@@ -59,7 +59,7 @@ fn G() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "function_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/array/iterate.carbon

@@ -179,7 +179,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "iterate.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/basics/empty.carbon

@@ -18,5 +18,5 @@
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "empty.carbon", directory: "")

toolchain/lower/testdata/builtins/bool.carbon

@@ -60,7 +60,7 @@ fn IfEq(a: Bool(), b: Bool()) -> Bool() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "bool.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestEq", linkageName: "_CTestEq.Main", scope: null, file: !3, line: 16, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/char.carbon

@@ -43,7 +43,7 @@ fn Example() -> char {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Example", linkageName: "_CExample.Main", scope: null, file: !3, line: 4, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/float.carbon

@@ -166,7 +166,7 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestNegate", linkageName: "_CTestNegate.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -249,7 +249,7 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "compound_assign.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestAdd", linkageName: "_CTestAdd.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -303,7 +303,7 @@ fn TestF128(a: f128, b: f128) -> f128 { return F128(a, b); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "types.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestF16", linkageName: "_CTestF16.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/int.carbon

@@ -365,7 +365,7 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestNegate", linkageName: "_CTestNegate.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -580,7 +580,7 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "compound_assign.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestSAdd", linkageName: "_CTestSAdd.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -722,7 +722,7 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "mixed_shift.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestLeftShiftSmaller", linkageName: "_CTestLeftShiftSmaller.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -850,7 +850,7 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "mixed_compare.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestEq_u16_u32", linkageName: "_CTestEq_u16_u32.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -974,7 +974,7 @@ fn TestUint32ToUint64(a: u32) -> u64 { return Uint32ToUint64(a); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "convert.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestInt32ToInt32", linkageName: "_CTestInt32ToInt32.Main", scope: null, file: !3, line: 10, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/int_literal.carbon

@@ -62,7 +62,7 @@ fn IntMin() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "int_literal.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Copy", linkageName: "_CCopy.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/maybe_unformed.carbon

@@ -151,7 +151,7 @@ fn PassAdapterBool() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "maybe_unformed.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TakeI32", linkageName: "_CTakeI32.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/method_vs_nonmethod.carbon

@@ -40,7 +40,7 @@ fn TestAddMethod(a: i32, b: i32) -> i32 { return a.(AddMethod)(b); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "method_vs_nonmethod.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestAddNonmethod", linkageName: "_CTestAddNonmethod.Main", scope: null, file: !3, line: 16, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/no_op.carbon

@@ -81,7 +81,7 @@ fn J() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "no_op.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/overloaded_operator.carbon

@@ -32,7 +32,7 @@ fn AddThreeIntegers(a: i32, b: i32, c: i32) -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "overloaded_operator.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "AddThreeIntegers", linkageName: "_CAddThreeIntegers.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/pointer.carbon

@@ -47,7 +47,7 @@ fn Check(p: MakeUnformed(C*)) -> bool {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "pointer.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Null", linkageName: "_CNull.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/print_read.carbon

@@ -75,7 +75,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "print_read.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main", linkageName: "_CMain.Main", scope: null, file: !3, line: 18, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/type.carbon

@@ -54,7 +54,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "can_destroy.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 5, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -79,7 +79,7 @@ fn F() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "destroy.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/types.carbon

@@ -56,7 +56,7 @@ fn Uses() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "types.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Uses", linkageName: "_CUses.Main", scope: null, file: !3, line: 28, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/builtins/uint.carbon

@@ -200,7 +200,7 @@ fn TestGreaterEq(a: u64, b: u64) -> bool { return GreaterEq(a, b); }
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "uint.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "TestNegate", linkageName: "_CTestNegate.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/adapt.carbon

@@ -111,7 +111,7 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "adapt_class.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Make", linkageName: "_CMake.PairOfInts.Main", scope: null, file: !3, line: 8, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -152,7 +152,7 @@ fn DoStuff(a: Int) -> Int {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "adapt_int.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Main:Copy.Core", scope: null, file: !3, line: 8, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/base.carbon

@@ -80,7 +80,7 @@ fn Convert(p: Derived*) -> Base* {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "base.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Make", linkageName: "_CMake.Main", scope: null, file: !3, line: 23, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/basic.carbon

@@ -52,7 +52,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/convert.carbon

@@ -71,7 +71,7 @@ fn DoIt() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "convert.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Convert", linkageName: "_CConvert.IntWrapper.Main:ImplicitAs.Core", scope: null, file: !3, line: 18, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/field.carbon

@@ -105,7 +105,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 9, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -156,7 +156,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "inplace_init_with_nonconst.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -203,7 +203,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "implicit_init_with_nonempty_nonconst.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/generic.carbon

@@ -110,7 +110,7 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "classes.carbon", directory: "")
 // CHECK:STDOUT: ; ModuleID = 'create.carbon'
 // CHECK:STDOUT: source_filename = "create.carbon"
@@ -145,7 +145,7 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "create.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "CreateDerived", linkageName: "_CCreateDerived.Create", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -233,7 +233,7 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "create_generic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Ints", linkageName: "_CInts.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -389,7 +389,7 @@ fn AccessTuple() -> (i32, i32, i32) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "access.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "AccessBool", linkageName: "_CAccessBool.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/import.carbon

@@ -37,7 +37,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "a.carbon", directory: "")
 // CHECK:STDOUT: ; ModuleID = 'b.carbon'
 // CHECK:STDOUT: source_filename = "b.carbon"
@@ -58,7 +58,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "b.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 3, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/method.carbon

@@ -44,7 +44,7 @@ fn F(p: C*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "method.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/method_addr.carbon

@@ -44,7 +44,7 @@ fn F(p: C*) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "method_addr.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/self.carbon

@@ -51,7 +51,7 @@ fn C.Set[ref self: C]() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "self.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Get", linkageName: "_CGet.C.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/self_addr.carbon

@@ -51,7 +51,7 @@ fn C.Set[addr self: C*]() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "self_addr.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Get", linkageName: "_CGet.C.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/value_access.carbon

@@ -53,7 +53,7 @@ fn F(c: C) -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "value_access.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/class/virtual.carbon

@@ -179,7 +179,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "classes.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Fn", linkageName: "_CFn.Intermediate.Classes", scope: null, file: !3, line: 9, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -254,7 +254,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "create.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Create", linkageName: "_CCreate.Create", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -323,7 +323,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "member_init.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Fn", linkageName: "_CFn.Base.MemberInit", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -373,7 +373,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "member_brace_init.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Use", linkageName: "_CUse.Main", scope: null, file: !3, line: 12, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -409,7 +409,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Use", linkageName: "_CUse.Main", scope: null, file: !3, line: 8, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -460,7 +460,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_impl.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Use", linkageName: "_CUse.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -478,7 +478,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "generic_noop.carbon", directory: "")
 // CHECK:STDOUT: ; ModuleID = 'generic_use.carbon'
 // CHECK:STDOUT: source_filename = "generic_use.carbon"
@@ -537,7 +537,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "generic_use.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -583,7 +583,7 @@ fn Make() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "generic_base.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Make", linkageName: "_CMake.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/for/bindings.carbon

@@ -158,7 +158,7 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "bindings.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !3, line: 26, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/for/break_continue.carbon

@@ -199,7 +199,7 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "break_continue.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/for/for.carbon

@@ -187,7 +187,7 @@ fn For() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "for.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "For", linkageName: "_CFor.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/empty_struct.carbon

@@ -47,7 +47,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "empty_struct.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Echo", linkageName: "_CEcho.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/empty_tuple.carbon

@@ -47,7 +47,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "empty_tuple.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Echo", linkageName: "_CEcho.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/i32.carbon

@@ -48,7 +48,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "i32.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Echo", linkageName: "_CEcho.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/implicit_empty_tuple_as_arg.carbon

@@ -60,7 +60,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "implicit_empty_tuple_as_arg.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/params_one.carbon

@@ -39,7 +39,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_one.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/params_one_comma.carbon

@@ -41,7 +41,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_one_comma.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/params_two.carbon

@@ -39,7 +39,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_two.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/params_two_comma.carbon

@@ -41,7 +41,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_two_comma.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/params_zero.carbon

@@ -39,7 +39,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_zero.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/ref_param.carbon

@@ -47,7 +47,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "ref_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "DoNothing", linkageName: "_CDoNothing.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/return_implicit.carbon

@@ -47,7 +47,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "return_implicit.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "MakeImplicitEmptyTuple", linkageName: "_CMakeImplicitEmptyTuple.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/struct_param.carbon

@@ -41,7 +41,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "struct_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/tuple_param.carbon

@@ -41,7 +41,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "tuple_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/tuple_param_with_return_slot.carbon

@@ -60,7 +60,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "tuple_param_with_return_slot.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/call/var_param.carbon

@@ -48,7 +48,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "var_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "DoNothing", linkageName: "_CDoNothing.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/declaration/simple.carbon

@@ -41,7 +41,7 @@ fn I() -> A;
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "simple.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/destroy.carbon

@@ -111,7 +111,7 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "let_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -161,7 +161,7 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "var_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -231,7 +231,7 @@ fn InitLet() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "return_slot.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/empty_struct.carbon

@@ -29,7 +29,7 @@ fn Echo(a: {}) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "empty_struct.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Echo", linkageName: "_CEcho.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/params_one.carbon

@@ -28,7 +28,7 @@ fn Foo(a: i32) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_one.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/params_two.carbon

@@ -28,7 +28,7 @@ fn Foo(a: i32, b: i32) {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_two.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/params_zero.carbon

@@ -28,7 +28,7 @@ fn Foo() {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "params_zero.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/raw_name.carbon

@@ -29,7 +29,7 @@ fn r#self() {}
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "raw_name.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "self", linkageName: "_Cself.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/definition/var_param.carbon

@@ -114,7 +114,7 @@ fn Call() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "var_param.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "OneVar_i32", linkageName: "_COneVar_i32.Main", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call.carbon

@@ -106,7 +106,7 @@ fn G() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_basic.carbon

@@ -245,7 +245,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Op", linkageName: "_COp.C.Main:Copy.Core", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_basic_depth.carbon

@@ -92,7 +92,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_basic_depth.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 30, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_dedup_ptr.carbon

@@ -65,7 +65,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_dedup_ptr.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_deref_ptr.carbon

@@ -130,7 +130,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_deref_ptr.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 35, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_different_associated_const.carbon

@@ -70,7 +70,7 @@ fn H() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_different_associated_const.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "H", linkageName: "_CH.Main", scope: null, file: !3, line: 35, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_different_impls.carbon

@@ -86,7 +86,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_different_impls.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_different_impls_with_const.carbon

@@ -110,7 +110,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_different_impls_with_const.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !3, line: 21, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_different_specific.carbon

@@ -137,7 +137,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_different_specific.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 42, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_impl_function.carbon

@@ -74,7 +74,7 @@ fn G() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_impl_function.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.ImplsSomeInterface.Main:SomeInterface.Main", scope: null, file: !3, line: 22, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_method.carbon

@@ -65,7 +65,7 @@ fn CallF() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_method.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "CallF", linkageName: "_CCallF.Main", scope: null, file: !3, line: 19, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_basic.carbon

@@ -161,7 +161,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_basic.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Op", linkageName: "_COp.C.Main:Copy.Core", scope: null, file: !3, line: 15, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_diamond.carbon

@@ -247,7 +247,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_diamond.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 47, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_impl.carbon

@@ -112,7 +112,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_impl.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_mutual.carbon

@@ -173,7 +173,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_mutual.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 32, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_reorder.carbon

@@ -79,7 +79,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_reorder.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 22, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_reorder_more.carbon

@@ -249,7 +249,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_reorder_more.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 22, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_recursive_sccs_deep.carbon

@@ -360,7 +360,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_recursive_sccs_deep.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 73, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/call_specific_in_class.carbon

@@ -183,7 +183,7 @@ fn M() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "call_specific_in_class.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 32, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/cross_library_name_collision_private.carbon

@@ -59,7 +59,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "lib1.carbon", directory: "")
 // CHECK:STDOUT: ; ModuleID = 'lib2.carbon'
 // CHECK:STDOUT: source_filename = "lib2.carbon"
@@ -69,7 +69,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "lib2.carbon", directory: "")
 // CHECK:STDOUT: ; ModuleID = 'todo_use.carbon'
 // CHECK:STDOUT: source_filename = "todo_use.carbon"
@@ -109,7 +109,7 @@ fn Run() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "todo_use.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 9, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/import.carbon

@@ -74,7 +74,7 @@ fn Call() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "indirectly_imported.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "IndirectDefined", linkageName: "_CIndirectDefined.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -98,7 +98,7 @@ fn Call() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "directly_imported.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "DirectDefined", linkageName: "_CDirectDefined.Main", scope: null, file: !3, line: 8, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
@@ -159,7 +159,7 @@ fn Call() -> i32 {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "use.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Call", linkageName: "_CCall.Main", scope: null, file: !3, line: 6, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/reverse_canonical.carbon

@@ -170,7 +170,7 @@ fn Main() {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "reverse_canonical.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main", linkageName: "_CMain.Main", scope: null, file: !3, line: 43, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/self_canonical.carbon

@@ -167,7 +167,7 @@ fn Main_method_no_template () {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "self_canonical.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Main_method_no_template", linkageName: "_CMain_method_no_template.Main", scope: null, file: !3, line: 79, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/function/generic/type_param.carbon

@@ -23,5 +23,5 @@ fn F(T:! type) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "type_param.carbon", directory: "")

toolchain/lower/testdata/function/generic/type_representation.carbon

@@ -231,7 +231,7 @@ fn F_nested_tuple(a: ((i32, i32), X)) -> ((i32, i32), X) {
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "type_representation.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Op", linkageName: "_COp.Int.Core:Copy.Main", scope: null, file: !3, line: 23, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/global/class_obj.carbon

@@ -38,7 +38,7 @@ var a: A = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "class_obj.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "__global_init", linkageName: "_C__global_init.Main", scope: null, file: !3, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/global/class_with_fun.carbon

@@ -52,7 +52,7 @@ var a: A = {};
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "class_with_fun.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "ret_a", linkageName: "_Cret_a.Main", scope: null, file: !3, line: 14, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/global/decl.carbon

@@ -21,5 +21,5 @@ var a: i32;
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "decl.carbon", directory: "")

toolchain/lower/testdata/global/simple_init.carbon

@@ -31,7 +31,7 @@ var a: i32 = 0;
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "simple_init.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "__global_init", linkageName: "_C__global_init.Main", scope: null, file: !3, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)

toolchain/lower/testdata/global/simple_with_fun.carbon

@@ -43,7 +43,7 @@ var a: i32 = test_a();
 // CHECK:STDOUT:
 // CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
 // CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
-// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
 // CHECK:STDOUT: !3 = !DIFile(filename: "simple_with_fun.carbon", directory: "")
 // CHECK:STDOUT: !4 = distinct !DISubprogram(name: "test_a", linkageName: "_Ctest_a.Main", scope: null, file: !3, line: 13, type: !5, spFlags: DISPFlagDefinition, unit: !2)
 // CHECK:STDOUT: !5 = !DISubroutineType(types: !6)