[llvm] Patch tryCanonicalizeStructToVector to handle split slice tails (PR #201434)

[Yaxun Liu via llvm-commits]

https://github.com/yxsamliu approved this pull request.

LGTM. The split-tail check is the right missing legality condition here, and it matches how other SROA partition checks account for overlapping slices. My comments are minor clarity/test-strength suggestions and not blocking.

https://github.com/llvm/llvm-project/pull/201434