[llvm] [LV][NFC] Reorder creating vplans for UserVF and epilogueVF (PR #214379)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

> This change is needed for this PR: https://github.com/llvm/llvm-project/pull/208764
We need to create the epilogue vplan later because it could be replace by a new vplan if we enable epilogue-tail-folding.

I would have been good to include the rational in the commit message.

https://github.com/llvm/llvm-project/pull/214379