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

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

I'd expect you to place an actual phi node (which combines one predicated input and other non-predicated input), not a new type of predicate.

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