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

[Rajveer Singh Bharadwaj via llvm-commits]

Rajveer100 wrote:

> Description still mentions ssa copy but that's not involved

Yeah, it should bechanged to `bitcast`. By the way, what do you think about the patch itself, removing `PredicatePHI` should be done here as suggested or something that can be potential follow up?

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