[llvm] [AMDGPU] Cgscc amdgpu attributor (PR #179719)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

The set of attributes should be split up into cgscc and module variants. However, it may be more convenient to do that in a follow up patch that adds cgscc to the default pipeline 

https://github.com/llvm/llvm-project/pull/179719