[llvm] [InstCombine] Fold xored one-complemented operand comparisons (PR #69882)

[via llvm-commits]

goldsteinn wrote:

> > @dtcxzyw why did the build fail?
> 
> You should add `Value *C` to shadow the definition `const APInt *C` in the outer scope.

Or instead rename variables to X/Y/Z as shadow variables can cause confusion and in llvm `C` usually means constant which isn't the case here.

https://github.com/llvm/llvm-project/pull/69882