[llvm] [LV] Move 3 functions into VPlanTransforms (NFC) (PR #158644)

[Florian Hahn via llvm-commits]

fhahn wrote:

@artagnon looks there a test failures with expensive checks which looks related to the patch: https://lab.llvm.org/buildbot/#/builders/187/builds/12178.

Is it possible that some stale code got moved?

https://github.com/llvm/llvm-project/pull/158644