[MachineVerifier] Try harder to verify LiveIntervals

[MachineVerifier] Try harder to verify LiveIntervals

Verify the LiveIntervals analysis after a pass that claims to preserve
it, even if there are no further passes (apart from the verifier itself)
that would use the analysis.

Fixes https://github.com/llvm/llvm-project/issues/46217

Differential Revision: https://reviews.llvm.org/D129208