[llvm] [ARM] Lower isnan(x) | isnan(never-nan) to x != x, and lower !isnan(x) & !isnan(never-nan) to x == x (PR #194932)

[John Brawn via llvm-commits]

john-brawn-arm wrote:

This looks like something that would be better done in DAGCombiner, as there's nothing target-specific here (assuming an eq/ne check is always at least as efficient as a o/uo check, which I think is a safe assumption).

https://github.com/llvm/llvm-project/pull/194932