[llvm] [InstSimplify] Enable FAdd simplifications when user can ignore sign bit (PR #157757)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> Made the changes as proposed, also changed canIgnoreSignBitOfNaN for uniformity.

This reverts the previous change asked by https://github.com/llvm/llvm-project/pull/141015#discussion_r2102772571 :)
You should put your code in InstCombine instead of InstSimplify, if it checks the users.


https://github.com/llvm/llvm-project/pull/157757