[llvm] [AMDGPU] Improved Lowering of abs(i16) and -abs(i16) (PR #165626)

[Jay Foad via llvm-commits]

jayfoad wrote:

> Why aren't you just using setOperationAction promotion?

I guess that would work for i16 (which is legal) but not for i8 (which is not).

https://github.com/llvm/llvm-project/pull/165626