[llvm] [MachineVerifier] Query TargetInstrInfo for PHI nodes. (PR #110507)

[Nathan Gauër via llvm-commits]

Keenuts wrote:

Thanks for the reviews!
@arsenm @michalpaszkowski : I wasn't at the dev meeting, addressed the review comments (and also added the test for the duplicated predecessor), but unsure what's the status on the approval.

https://github.com/llvm/llvm-project/pull/110507