[llvm] [AMDGPU][MC] Disallow nogds in ds_gws_* instructions (PR #166438)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

I don't understand this. Has "nogds" ever been a modifier? I do not see that in any tests 

https://github.com/llvm/llvm-project/pull/166438