[llvm] [InstCombine] Remove scalable vector extracts to and from the same type (PR #69702)

[David Sherwood via llvm-commits]

https://github.com/david-arm approved this pull request.

LGTM! I suggested a possible tweak you could make before landing the patch, but only if you think it's worth it. :)

https://github.com/llvm/llvm-project/pull/69702