[llvm] Scalarizer : Fix vector shuffle issue when can't aligned to customized minBits. (PR #163912)

[Nicolai Hähnle via llvm-commits]

https://github.com/nhaehnle commented:

Can you give more context as for what this is trying to achieve? The LLVM IR that the pass produces for your test looks pretty reasonable to me, except as noted in the comment.

Naively, I'd think that a long sequence of extractelement/insertelement seems inherently worse than a pair of shufflevectors.

https://github.com/llvm/llvm-project/pull/163912