backport request: [x86] invert a vector select IR canonicalization with a binop identity constant

[rotateright]

This will mitigate a potential perf regression from the last release as discussed here:
https://reviews.llvm.org/D113442

/cherry-pick 6592bce

[llvmbot]

@llvm/issue-subscribers-backend-x86

[tstellar]

/cherry-pick 6592bce

[llvmbot]

/branch llvmbot/llvm-project/issue53656

[llvmbot]

/pull-request llvmbot#20

[rotateright]

Thanks @tstellar ! Did I file this as needed with the label and milestone set?
There are 2 more follow-on patches to this one that I'd like to get into the branch, so please let me know if I can reduce/automate things better for you.

[tstellar]

@rotateright The milestone is correct. The only thing is that the cherry-pick command only works in a comment at the moment and not in in the issue body (i.e. the first comment), but I'm working on fixing that.

If you have other commits, it's going to be easier to just create a new issue for them.

[rotateright]

@rotateright The milestone is correct. The only thing is that the cherry-pick command only works in a comment at the moment and not in in the issue body (i.e. the first comment), but I'm working on fixing that.

Aha - I didn't know about that detail.

If you have other commits, it's going to be easier to just create a new issue for them.

Sure, will do. The other parts just went into main today, so I'll give them at least a day to bake.

[tstellar]

Merged: a2f5832