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

[Matt Arsenault via llvm-commits]

================
@@ -16625,20 +16638,33 @@ type.
 
 Semantics:
 """"""""""
-Follows the IEEE-754 semantics for maxNum except for the handling of
-signaling NaNs. This matches the behavior of libm's fmax.
+Follows the semantics of maxinumNumber in IEEE-754-2019, except for signaling NaNs. If either operand
----------------
arsenm wrote:

Typo maxinumNumber. Same comments as above for minnum 

https://github.com/llvm/llvm-project/pull/112852