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

[Rajveer Singh Bharadwaj via llvm-commits]

Rajveer100 wrote:

The split up into lambdas would definitely make it cleaner, for example:

- the swapping part
- cost calculation
- bit masks
- initial parity mask.

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