[llvm] Revert "Revert "LangRef: Clarify llvm.minnum and llvm.maxnum about sNaN and signed zero (#112852)"" (PR #170067)

[Phoebe Wang via llvm-commits]

phoebewang wrote:

@arsenm I'm confusing here. If you believe we can revert a patch arbitrarily as long as we don't agree with it. You shouldn't block a simple revert like #138451 and revert a revert patch. The holiday reason also surprises me. I'd not be surprised if anyone revert it use it. But you are in the reviewer list at the beginning when the patch created on 20th and you were active till 27th according to GH record. So my understanding was you don't object it at least.

https://github.com/llvm/llvm-project/pull/170067