[llvm] [AMDGPU] Autogenerate VOP3 literal checks (PR #156038)

[David Stuttard via llvm-commits]

dstutt wrote:

> LGTM
> 
> EDIT, modulo comment about grep. Before approving I did check that there were already "grep" present in the existing tests, just didn't know about the deprecation.

But not in AMDGPU tests?

https://github.com/llvm/llvm-project/pull/156038