[llvm] [AMDGPU] Add MachineVerifier check to detect illegal copies from vector register to SGPR (PR #105494)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-debian` running on `gribozavr4` while building `llvm` at step 6 "test-build-unified-tree-check-all".
> 
> Full details are available at: https://lab.llvm.org/buildbot/#/builders/16/builds/5632
> 
> Here is the relevant piece of the build log for the reference

Fixed f9bd08382a4ad84c06e0b572d3b7fc3ecdb81898

https://github.com/llvm/llvm-project/pull/105494