[llvm] [VPlan] Extend getSCEVForVPV, use to compute VPReplicateRecipe cost. (PR #161276)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

Modulo the code duplication (which is pending a decision), the rest looks good.

https://github.com/llvm/llvm-project/pull/161276