Add a convenience method for dumping the formatted SemIR file. (#4123)

toolchain/check/BUILD

@@ -69,6 +69,7 @@ cc_library(
         "//toolchain/parse:tree_node_diagnostic_converter",
         "//toolchain/sem_ir:builtin_inst_kind",
         "//toolchain/sem_ir:file",
+        "//toolchain/sem_ir:formatter",
         "//toolchain/sem_ir:ids",
         "//toolchain/sem_ir:inst",
         "//toolchain/sem_ir:inst_kind",

toolchain/check/context.cpp

@@ -23,6 +23,7 @@
 #include "toolchain/parse/node_kind.h"
 #include "toolchain/sem_ir/builtin_inst_kind.h"
 #include "toolchain/sem_ir/file.h"
+#include "toolchain/sem_ir/formatter.h"
 #include "toolchain/sem_ir/ids.h"
 #include "toolchain/sem_ir/import_ir.h"
 #include "toolchain/sem_ir/inst.h"
@@ -1197,4 +1198,8 @@ auto Context::PrintForStackDump(llvm::raw_ostream& output) const -> void {
   args_type_info_stack_.PrintForStackDump(output);
 }
 
+auto Context::DumpFormattedFile() const -> void {
+  FormatFile(*tokens_, *parse_tree_, *sem_ir_, llvm::errs());
+}
+
 }  // namespace Carbon::Check

toolchain/check/context.h

@@ -345,6 +345,9 @@ class Context {
   // Prints information for a stack dump.
   auto PrintForStackDump(llvm::raw_ostream& output) const -> void;
 
+  // Prints the the formatted sem_ir to stderr.
+  LLVM_DUMP_METHOD auto DumpFormattedFile() const -> void;
+
   // Get the Lex::TokenKind of a node for diagnostics.
   auto token_kind(Parse::NodeId node_id) -> Lex::TokenKind {
     return tokens().GetKind(parse_tree().node_token(node_id));