[clang] [CIR][AMDGPU] Add module flags for AMDGPU target using amendOperation of CIRDialectLLVMIRTranslationInterface (PR #186073)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor approved this pull request.

lgtm with a couple of minor suggestions

https://github.com/llvm/llvm-project/pull/186073