[llvm] [VectorCombine] foldShuffleToIdentity - handle bitcasts with equal element counts (PR #97731)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

I'm AFK until tomorrow now, but if you can post the regression I'll take a look as soon as I can.

https://github.com/llvm/llvm-project/pull/97731