Add range flag settings to package-expr files (#5568)

Where `--no-dump-sem-ir` is used, change to `--dump-sem-ir-ranges=only`.
Otherwise, add `--dump-sem-ir-ranges=if-present` with a TODO to change
to `only`.

Note, SemIR is affected just because the extra comments change line
numbers in files where splits aren't in use.

toolchain/check/testdata/package_expr/fail_not_found.carbon

@@ -2,6 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
+// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
 // TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/package_expr/fail_not_found.carbon
@@ -57,7 +60,7 @@ fn Main() {
 // CHECK:STDOUT:   %package.ref: <namespace> = name_ref package, package [concrete = package]
 // CHECK:STDOUT:   %x.ref: <error> = name_ref x, <error> [concrete = <error>]
 // CHECK:STDOUT:   assign %y.var, <error>
-// CHECK:STDOUT:   %.loc16: type = splice_block %i32 [concrete = constants.%i32] {
+// CHECK:STDOUT:   %.loc19: type = splice_block %i32 [concrete = constants.%i32] {
 // CHECK:STDOUT:     %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
 // CHECK:STDOUT:     %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
 // CHECK:STDOUT:   }

toolchain/check/testdata/package_expr/syntax.carbon

@@ -2,6 +2,9 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
+// TODO: Add ranges and switch to "--dump-sem-ir-ranges=only".
+// EXTRA-ARGS: --dump-sem-ir-ranges=if-present
+//
 // AUTOUPDATE
 // TIP: To test this file alone, run:
 // TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/package_expr/syntax.carbon