[llvm] [Instructions] cache computed shufflevector properties (PR #115536)

[Princeton Ferro via llvm-commits]

Prince781 wrote:

Hi @RKSimon 

While this improves the original case I was interested in, I'm finding with a newer kernel we recently added that the 8b size increase for ShuffleVectorInst is causing (CPU) caching problems. So I'd like to still hold off on merging.

https://github.com/llvm/llvm-project/pull/115536