[clang] [CIR][SPIR-V] Keep atomic sync scopes (PR #231754)

[Steffen Larsen via cfe-commits]

https://github.com/steffenlarsen commented:

Conceptually good, but I wonder if it makes more sense to expand the target info hook space instead of diverging inside `SPIRVTargetLoweringInfo`

https://github.com/llvm/llvm-project/pull/231754