[clang] [clang][analyzer] Fix the false positive ArgInitializedness warning on unnamed bit-field (PR #145066)

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Tedlion wrote:

@vbvictor Thank you for your help. But the Build and Test Windows " fails:
`llvm-lit.py: C:\_work\llvm-project\llvm-project\llvm\utils\lit\lit\llvm\config.py:312: fatal: Couldn't find the include dir for Clang ('c:\_work\llvm-project\llvm-project\build\bin\clang.exe')`
It seems not causing by my commit. Would you please help me with this?

https://github.com/llvm/llvm-project/pull/145066