[llvm] [LV] optimize VF for low TC, when tail-folding (PR #91253)

[Ramkumar Ramachandra via llvm-commits]

artagnon wrote:

> Just checking, did you do some performance runs with this? Can you share some results?

I thought the change was a logical fix, and that the test updates made it clear what exactly the change was doing. I didn't think it was necessary to do performance benchmarking for this patch: besides, I don't have access to the necessary infrastructure at the moment.

https://github.com/llvm/llvm-project/pull/91253