[clang] [Clang][Driver] Add new flags to control machine instruction verification (PR #70282)

[Nikita Popov via cfe-commits]

nikic wrote:

I'm not convinced that adding this flag makes sense, given that you can already use `-mllvm -verify-machineinstrs`. This is a developer option, and I don't think it should be exposed by the clang driver (and if you expose it in cc1 only, then `-Xclang -fverify-machine-code` is really no better than `-mllvm -verify-machineinstrs`). We have a lot of different verification options for different things, and I don't think they should be exposed to end users.

https://github.com/llvm/llvm-project/pull/70282