[llvm] [InstCombine] canonicalize operands of fcmp ord/uno if they are known NaN (PR #97763)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

Please update the title and description, since this PR folds the pattern into a constant instead of canonicalizing its operands.
 

https://github.com/llvm/llvm-project/pull/97763