[clang] Clang: Add minnum/maxnum builtin functions (PR #129207)

[Matt Arsenault via cfe-commits]

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@@ -209,6 +209,18 @@ def FmaxF16F128 : Builtin, F16F128MathTemplate {
   let Prototype = "T(T, T)";
 }
 
+def MinNum : Builtin {
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arsenm wrote:

Should the keep the f prefix convention? I suppose we aren't following a libm function, so it might make sense to drop it 

https://github.com/llvm/llvm-project/pull/129207