[llvm] [VPlan] Add VPValue for VF, use it for VPWidenIntOrFpInductionRecipe. (PR #95305)

[via llvm-commits]

https://github.com/ayalz approved this pull request.

LGTM, with minor nits, also note several earlier thoughts - replace optimizeForVFAndUF() by setVF() and setUF(), rename "RuntimeVF", and few comments in tests.

https://github.com/llvm/llvm-project/pull/95305