[llvm] [X86] Add DAG combiner for X86ISD::XOR to eliminate redundant XORs (PR #216134)

[Craig Topper via llvm-commits]

topperc wrote:

Once again you are force pushing to change the last commit. This is against our pull request guidelines. https://llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes

https://github.com/llvm/llvm-project/pull/216134