[llvm] [SPIRV] Add verify-machineinstrs option (PR #193782)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm requested changes to this pull request.

Definitely do not do this. Most -verify-machineinstrs should be removed from tests. If you want to unconditionally use -verify-machineinstrs, use an EXPENSIVE_CHECKS build. It makes no sense to add this clutter to every single test 

https://github.com/llvm/llvm-project/pull/193782