[llvm] [MachineVerifier] Fix LiveInterval verification of unwinding instructions (PR #131565)

[Heejin Ahn via llvm-commits]

aheejin wrote:

What cases does this check cover? I thought the below was the case; please let me know if this is not correct.
> But if the call has a possibility to unwind to an EH pad, it means it was an invoke before and it should either be the terminating instruction of a BB or be right before a branch, which is the terminator. If a call is in a middle of a BB, that means the call was not an invoke before and it unwinds to the caller if it throws.

https://github.com/llvm/llvm-project/pull/131565