[clang] [clang-format] Add ClassHeadName to help annotating StartOfName (PR #124891)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-aarch64-dylib` running on `linaro-flang-aarch64-dylib` while building `clang` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/50/builds/9666

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (build-unified-tree) failure: build (failure)
...
334.903 [1007/1/5792] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPISPIRV.dir/SPIRV.cpp.o
335.008 [1006/1/5793] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPITensor.dir/Tensor.cpp.o
335.132 [1005/1/5794] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPITransformDialect.dir/Transform.cpp.o
335.248 [1004/1/5795] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPITransformDialectTransforms.dir/TransformInterpreter.cpp.o
335.360 [1003/1/5796] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIQuant.dir/Quant.cpp.o
335.612 [1002/1/5797] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIOpenMP.dir/OpenMP.cpp.o
335.714 [1001/1/5798] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIPDL.dir/PDL.cpp.o
335.843 [1000/1/5799] Building CXX object tools/mlir/lib/CAPI/Dialect/CMakeFiles/obj.MLIRCAPIVector.dir/Vector.cpp.o
336.020 [999/1/5800] Building CXX object tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestSPIRVCPURunnerPipeline.cpp.o
346.516 [998/1/5801] Building CXX object tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestPassManager.cpp.o
FAILED: tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestPassManager.cpp.o 
/usr/local/bin/c++ -DGTEST_HAS_RTTI=0 -DMLIR_INCLUDE_TESTS -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/Pass -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/Pass -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/llvm/include -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/Pass/../Dialect/Test -I/home/tcwg-buildbot/worker/flang-aarch64-dylib/build/tools/mlir/test/lib/Pass/../Dialect/Test -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wundef -Werror=mismatched-tags -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -fno-rtti -UNDEBUG -MD -MT tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestPassManager.cpp.o -MF tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestPassManager.cpp.o.d -o tools/mlir/test/lib/Pass/CMakeFiles/MLIRTestPass.dir/TestPassManager.cpp.o -c /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/Pass/TestPassManager.cpp
In file included from /home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/Pass/TestPassManager.cpp:10:
/home/tcwg-buildbot/worker/flang-aarch64-dylib/llvm-project/mlir/test/lib/Pass/../Dialect/Test/TestOps.h:148:10: fatal error: 'TestOps.h.inc' file not found
  148 | #include "TestOps.h.inc"
      |          ^~~~~~~~~~~~~~~
1 error generated.
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/124891