[llvm] GlobalISel needs fdiv 1 / sqrt(x) to rsq combine (PR #78673)

[Nick Anderson via llvm-commits]

nickleus27 wrote:

Since #80526 landed first. I need to squash these fixup commits, and pull from upstream since the aforementioned commit will change the .mir in this patch. So once I update the .mir I will try back for review.

https://github.com/llvm/llvm-project/pull/78673