[llvm] [X86] combineConcatVectorOps - add concatenation handling for BITCAST nodes (PR #133913)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

Cheers, that's not much to go on I'm afraid. I can't tell if it's the patch's fault or if it's exposed an existing problem. Any luck with a reduced repro?

https://github.com/llvm/llvm-project/pull/133913