[llvm] [AMDGPU] Fix subtarget predicates for some V_MAD, V_FMA and V_DOT instructions. (PR #71194)

[Jay Foad via llvm-commits]

https://github.com/jayfoad approved this pull request.

LGTM.

How do you find these problems? Once they are all fixed can  you add some kind of assertion somewhere to stop them reoccuring?

https://github.com/llvm/llvm-project/pull/71194