[clang] [clang][DebugInfo][NFC] Simplify CollectRecordLambdaFields (PR #160690)

[Petr Hosek via cfe-commits]

petrhosek wrote:

We started seeing the assertion introduced in this PR to trigger on our builders:

```
FAILED: [code=1] host_x64/obj/third_party/android/platform/system/libbase/libbase.logging.cpp.o
../../prebuilt/third_party/clang/custom/bin/clang++ -MD -MF host_x64/obj/third_party/android/platform/system/libbase/libbase.logging.cpp.o.d -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES -I../.. -Ihost_x64/gen -I../../third_party/android/platform/system/libbase/include -I../../third_party/fmtlib/src/include -I../../third_party/android/platform/system/logging/libl...
clang++: clang/include/clang/AST/LambdaCapture.h:105: ValueDecl *clang::LambdaCapture::getCapturedVar() const: Assertion `capturesVariable() && "No variable available for capture"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.	Program arguments: ../../prebuilt/third_party/clang/custom/bin/clang++ -MD -MF host_x64/obj/third_party/android/platform/system/libbase/libbase.logging.cpp.o.d -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS -D_LIBCPP_REMOVE_TRANSITIVE_INCLUDES -I../.. -Ihost_x64/gen -I../../third_party/android/platform/system/libbase/include -I../../third_party/fmtlib/src/include -I../../third_party/android/platfo...
1.	<eof> parser at end of file
2.	Per-file LLVM IR generation
3.	../../third_party/android/platform/system/libbase/logging_splitters.h:49:13: Generating code for declaration 'android::base::SplitByLogdChunks'
#0 0x00005565e78313d8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (../../prebuilt/third_party/clang/custom/bin/clang+++0x93a13d8)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Fuchsia clang version 22.0.0git (https://llvm.googlesource.com/llvm-project 8553bd2b29ad2b17a9a884f14da6c43b606ec776)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: ../../prebuilt/third_party/clang/custom/bin
Build config: +assertions
clang++: note: diagnostic msg:
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang++: note: diagnostic msg: clang-crashreports/logging-a37c8e.cpp
clang++: note: diagnostic msg: clang-crashreports/logging-a37c8e.sh
clang++: note: diagnostic msg:

********************
```

You can download the reproducer from https://storage.googleapis.com/fuchsia-artifacts/builds/8702649026706718113/build-debug/clang-crashreports/logging-e0f475.tar.

Would it be possible to revert this PR while the issue is being investigated?

https://github.com/llvm/llvm-project/pull/160690