[llvm] [LV] Use wide lane masks as the canonical form when tail-folding & interleaving (PR #209484)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

It looks like this is causing a crash in the backend https://clang.godbolt.org/z/YG1r63oT3.

https://github.com/llvm/llvm-project/pull/209484