[llvm] [InstCombine] Fold (sub (xor X, (sext C)), (sext C)) => (select C (neg X), X) (PR #79417)

[Yingwei Zheng via llvm-commits]

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+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
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dtcxzyw wrote:

Don't add tests in `CodeGen`.

https://github.com/llvm/llvm-project/pull/79417