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

[Rajveer Singh Bharadwaj via llvm-commits]

https://github.com/Rajveer100 commented:

So I managed to get the predicate information correctly work and get the final output as well:

```llvm
store i32 0, ptr @p, align 4
```

More info below.

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