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

[Shilei Tian via llvm-commits]

shiltian wrote:

> No objection for .ll test. Maybe keep it in .mir because it is very easy to write a mir which does not pass verification.

Restored MIR tests. Only IR tests are updated in this PR now.

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