[clang] [Clang] support storage-class specifiers in C23 compound literals (PR #212559)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

The serialization change is small and trivial. I don't give a LGTM as the size of the patch is too large and the serialization change is too small  in it .

https://github.com/llvm/llvm-project/pull/212559