[llvm] [RFC][NFC][AMDGPU] Remove `-verify-machineinstrs` from `llvm/test/CodeGen/AMDGPU/` (PR #150024)

[Jay Foad via llvm-commits]

jayfoad wrote:

No objection from me.

I have previously used `-verify-machineinstrs` when I've added a regression test for a bug that was originally only detected with EXPENSIVE_CHECKS. But I guess it is not necessary to keep it.

https://github.com/llvm/llvm-project/pull/150024