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

[Oleksandr Tarasiuk via cfe-commits]

a-tarasyuk wrote:

@nickdesaulniers, this is ready. I’d just like to get @AaronBallman’s feedback before merging. Just to clarify, this PR doesn’t add the lifetime intrinsics discussed in #68746.

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