Fix up after suggestions.

Author: zygoloid

toolchain/check/cpp/import.cpp

@@ -1697,7 +1697,7 @@ auto ImportCppFunctionDecl(Context& context, SemIR::LocId loc_id,
     Diagnostics::AnnotationScope annotate_diagnostics(
         &context.emitter(), [&](auto& builder) {
           CARBON_DIAGNOSTIC(InCppThunk, Note,
-                            "in thunk for Cpp function used here");
+                            "in thunk for C++ function used here");
           builder.Note(loc_id, InCppThunk);
         });
 

toolchain/check/cpp/location.cpp

@@ -43,7 +43,7 @@ auto GetCppLocation(Context& context, SemIR::LocId loc_id)
   // final entry.
   auto absolute_node_id = absolute_node_ids.back();
   const auto* ir = GetFile(context, absolute_node_id.check_ir_id());
-  CHECK(ir, "Node location points at nonexistent IR");
+  CARBON_CHECK(ir, "Node location points at nonexistent IR");
   const auto& tree = ir->parse_tree();
   const auto& source = tree.tokens().source();
   auto offset =
@@ -56,7 +56,7 @@ auto GetCppLocation(Context& context, SemIR::LocId loc_id)
   auto file = src_mgr.getFileManager().getOptionalFileRef(source.filename());
   if (!file) {
     file = src_mgr.getFileManager().getVirtualFileRef(
-        source.filename(), source.text.size(), /*ModificationTime=*/0);
+        source.filename(), source.text().size(), /*ModificationTime=*/0);
   }
   src_mgr.overrideFileContents(
       *file, llvm::MemoryBufferRef(source.text(), source.filename()));

toolchain/check/testdata/interop/cpp/function/class.carbon

@@ -153,7 +153,7 @@ import Cpp library "non_copyable_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_import_non_copyable_param_type.carbon:[[@LINE+4]]:3: note: in thunk for Cpp function used here [InCppThunk]
+  // CHECK:STDERR: fail_import_non_copyable_param_type.carbon:[[@LINE+4]]:3: note: in thunk for C++ function used here [InCppThunk]
   // CHECK:STDERR:   Cpp.foo({} as Cpp.C);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
@@ -414,7 +414,7 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for Cpp function used here [InCppThunk]
+  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for C++ function used here [InCppThunk]
   // CHECK:STDERR:   Cpp.foo();
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR:

toolchain/check/testdata/interop/cpp/function/struct.carbon

@@ -153,7 +153,7 @@ import Cpp library "non_copyable_param_type.h";
 
 fn F() {
   //@dump-sem-ir-begin
-  // CHECK:STDERR: fail_import_non_copyable_param_type.carbon:[[@LINE+4]]:3: note: in thunk for Cpp function used here [InCppThunk]
+  // CHECK:STDERR: fail_import_non_copyable_param_type.carbon:[[@LINE+4]]:3: note: in thunk for C++ function used here [InCppThunk]
   // CHECK:STDERR:   Cpp.foo({} as Cpp.S);
   // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~
   // CHECK:STDERR:
@@ -413,7 +413,7 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for Cpp function used here [InCppThunk]
+  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for C++ function used here [InCppThunk]
   // CHECK:STDERR:   Cpp.foo();
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR:

toolchain/check/testdata/interop/cpp/function/union.carbon

@@ -375,7 +375,7 @@ library "[[@TEST_NAME]]";
 import Cpp library "decl_value_return_type.h";
 
 fn F() {
-  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for Cpp function used here [InCppThunk]
+  // CHECK:STDERR: fail_import_decl_value_return_type.carbon:[[@LINE+13]]:3: note: in thunk for C++ function used here [InCppThunk]
   // CHECK:STDERR:   Cpp.foo();
   // CHECK:STDERR:   ^~~~~~~~~
   // CHECK:STDERR: