[llvm] [InstCombine] Fold shuffled intrinsic operands with constant operands (PR #141300)

[Luke Lau via llvm-commits]

lukel97 wrote:

@dtcxzyw The LGTM'd version of this patch actually had a pretty embarrassing bug, I've fixed it in 575d406e2d38d3d2e4541b38f9ce4a69cd1e455d. I'd definitely appreciate another review if you have the time!

https://github.com/llvm/llvm-project/pull/141300