[llvm] [LoopVectorize] Ensure VPPredInstPHIRecipe only uses InsertElementInst (PR #159543)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

@AbhinavMir  Could you add a reduced test for the crash so it is a bit easier to figure out what's going wrong?

How does the VPlan look like before we crash? It might be something that is better fixed awhen we create/optimize the VPlan

https://github.com/llvm/llvm-project/pull/159543