[llvm] [VectorCombine] New folding pattern for extract/binop/shuffle chains (PR #145232)

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

I still think this is more complicated than needed as written.

Are you sure the check definitely can't be written as a for loop? Without having to keep a `ExpectedParityMask` and update it each time?

I'd really like to avoid a worklist given that we should know exactly how many nodes we need to match 

https://github.com/llvm/llvm-project/pull/145232