[llvm] [AMDGPU] Support image atomic no return instructions (PR #150742)

[Jay Foad via llvm-commits]

https://github.com/jayfoad commented:

The C++ parts look mostly OK to me.

I'd prefer if someone else could comment on the MIMGInstructions.td changes. It looks like they introduce a lot of duplication. @sstipano @mbrkusanin 

https://github.com/llvm/llvm-project/pull/150742