[llvm] [InstSimplify] Improve coverage for zero-shift-guard folding for rotate (PR #217033)

[Vimal Patel via llvm-commits]

pvimal816a wrote:

> Hi Vimal, Thank you for the PR, could you add some negative tests. I left some suggestions. Your solution also works for scalable vector, maybe it would be worth to add at least to one or 2 tests that type too, just because you added for fixed vector too.

Sure. I'll make the suggested changes in some time. Thanks for the review.

https://github.com/llvm/llvm-project/pull/217033