[llvm] Revert [LV] Move 3 functions into VPlanTransforms (NFC) (PR #162094)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> Can we keep them out of LV.cpp, but just don't run them via `runPass`? There are a few points in the pipeline where `runPass` cannot be used yet

Sounds good, I thought not calling runPass in certain places were oversights. I'll put up a new patch, and add appropriate comments.

https://github.com/llvm/llvm-project/pull/162094