[llvm] [PredicateInfo] Support existing `PredicateType` by adding `PredicatePHI` when needing introduction of phi nodes (PR #151132)

[Rajveer Singh Bharadwaj via llvm-commits]

Rajveer100 wrote:

I think we're on the same page.

So, from a performance standpoint what do you think is better? If I understand correctly, if we don't use bitcast we would need to replace all uses for the given `Op` we are dealing with?

Whereas, if we just let the predicate be, it doesn't need any further handling.

https://github.com/llvm/llvm-project/pull/151132