[clang] Reland #90786 ([BoundsSafety] Allow 'counted_by' attribute on pointers in structs in C) (PR #93121)

[Dan Liew via cfe-commits]

delcypher wrote:

Hmm looks like I'll have to tweak the assert. Looks like some unit tests don't specify the language.

```
FAIL: Clang-Unit :: CodeGen/./ClangCodeGenTests/5/16 (19428 of 19653)
******************** TEST 'Clang-Unit :: CodeGen/./ClangCodeGenTests/5/16' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:/Volumes/user_data/dev/llvm/llvm.org/main/builds/Debug_xc___sccache/tools/clang/unittests/CodeGen/./ClangCodeGenTests-Clang-Unit-78051-5-16.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=16 GTEST_SHARD_INDEX=5 /Volumes/user_data/dev/llvm/llvm.org/main/builds/Debug_xc___sccache/tools/clang/unittests/CodeGen/./ClangCodeGenTests
--

Note: This is test shard 6 of 16.
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from TBAAMetadataTest
[ RUN      ] TBAAMetadataTest.CTypedefFields2
LLVM ERROR: getLangStandardForKind() on unspecified kind
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  ClangCodeGenTests        0x0000000102c186e4 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 88
1  ClangCodeGenTests        0x0000000102c18cc8 PrintStackTraceSignalHandler(void*) + 28
2  ClangCodeGenTests        0x0000000102c1695c llvm::sys::RunSignalHandlers() + 152
3  ClangCodeGenTests        0x0000000102c19e30 SignalHandler(int) + 276
4  libsystem_platform.dylib 0x00000001813b9a24 _sigtramp + 56
5  libsystem_pthread.dylib  0x0000000181389cc0 pthread_kill + 288
6  libsystem_c.dylib        0x0000000181295a40 abort + 180
7  ClangCodeGenTests        0x0000000102ad60bc llvm::report_fatal_error(llvm::Twine const&, bool) + 364
8  ClangCodeGenTests        0x0000000102ad5f50 llvm::report_fatal_error(llvm::Twine const&, bool) + 0
9  ClangCodeGenTests        0x000000010388c44c clang::LangStandard::getLangStandardForKind(clang::LangStandard::Kind) + 88
10 ClangCodeGenTests        0x00000001048d565c clang::Parser::ParseLexedCAttributeList(clang::Parser::LateParsedAttrList&, bool, clang::ParsedAttributes*) + 144
11 ClangCodeGenTests        0x00000001048d6190 clang::Parser::ParseStructUnionBody(clang::SourceLocation, clang::TypeSpecifierType, clang::RecordDecl*) + 1724
12 ClangCodeGenTests        0x00000001048ff868 clang::Parser::ParseClassSpecifier(clang::tok::TokenKind, clang::SourceLocation, clang::DeclSpec&, clang::Parser::ParsedTemplateInfo&, clang::AccessSpecifier, bool, clang::Parser::DeclSpecContext, clang::ParsedAttributes&) + 8916
13 ClangCodeGenTests        0x00000001048ce33c clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*, clang::ImplicitTypenameContext) + 15492
14 ClangCodeGenTests        0x00000001048c5908 clang::Parser::ParseDeclarationSpecifiers(clang::DeclSpec&, clang::Parser::ParsedTemplateInfo&, clang::AccessSpecifier, clang::Parser::DeclSpecContext, clang::Parser::LateParsedAttrList*) + 124
15 ClangCodeGenTests        0x00000001048c54ac clang::Parser::ParseSimpleDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, bool, clang::Parser::ForRangeInit*, clang::SourceLocation*) + 260
16 ClangCodeGenTests        0x00000001048c5284 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) + 1060
17 ClangCodeGenTests        0x00000001049ddbd0 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) + 2196
18 ClangCodeGenTests        0x00000001049dc10c clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) + 2024
19 ClangCodeGenTests        0x00000001049db880 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) + 64
20 ClangCodeGenTests        0x00000001048ac1c8 clang::ParseAST(clang::Sema&, bool, bool) + 476
21 ClangCodeGenTests        0x00000001024b1824 llvm::TestCompiler::compile() + 48
22 ClangCodeGenTests        0x00000001024c1024 (anonymous namespace)::TBAAMetadataTest_CTypedefFields2_Test::TestBody() + 236
23 ClangCodeGenTests        0x0000000102c9cf40 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 132
24 ClangCodeGenTests        0x0000000102c6be7c void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) + 96
25 ClangCodeGenTests        0x0000000102c6bdcc testing::Test::Run() + 192
26 ClangCodeGenTests        0x0000000102c6c894 testing::TestInfo::Run() + 304
27 ClangCodeGenTests        0x0000000102c6d768 testing::TestSuite::Run() + 412
28 ClangCodeGenTests        0x0000000102c77ee4 testing::internal::UnitTestImpl::RunAllTests() + 1024
29 ClangCodeGenTests        0x0000000102ca8248 bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 132
30 ClangCodeGenTests        0x0000000102c77a58 bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) + 96
31 ClangCodeGenTests        0x0000000102c7796c testing::UnitTest::Run() + 192
32 ClangCodeGenTests        0x0000000102c597b8 RUN_ALL_TESTS() + 16
33 ClangCodeGenTests        0x0000000102c5979c main + 192
34 dyld                     0x00000001810090e0 start + 2360
```

https://github.com/llvm/llvm-project/pull/93121