[llvm] [VPlan] Only fold ExtractLastLane if op is generates single-scalar. (PR #222448)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

A similar use-site of https://github.com/llvm/llvm-project/pull/196181: https://github.com/llvm/llvm-project/pull/216445.

https://github.com/llvm/llvm-project/pull/222448