[llvm] [VPlan][LV] Add removeRedundantAndMasks to VPlanTransforms (PR #163534)

[Nashe Mncube via llvm-commits]

nasherm wrote:

I believe I have an alternative fix for this problem which will exist in LoopFlatten alone. I think this would be a better solution for two reasons
1. the redundant AND masks are introduced due to the LoopFlatten widening IVs to compute the new tripcount. Keeping the fix in LoopFlatten keeps things self-contained
2. Porting my initial pass to VPlan is proving to be an inelegant solution.

I've opened another PR #166156 and will be closing this one.

https://github.com/llvm/llvm-project/pull/163534