[llvm] [LV] Add support for partial alias masking with tail folding (PR #182457)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

> Do we need to bring back something along the lines of #183066 as with the alias mask we may up with a non-power-of-2 effective VF/IV increment?

I've already done that. Have a look inside `LoopVectorizationPlanner::materializeAliasMask`.


https://github.com/llvm/llvm-project/pull/182457