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

[via cfe-commits]

skc7 wrote:

> I'd prefer to see this combined with #186081 so that the functionality is tested as it is added and only parts that are needed are added.

Thanks for feedback @andykaylor.
Merged #186081 into this PR

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