[turbofan] Add Float32(Max|Min) machine operators.

src/utils.h

Index: src/utils.h
diff --git a/src/utils.h b/src/utils.h
index a58439971f4c1f5ac291c7188a703a5b404946e3..8eca39207d4aa55b222870a2e36e7ce53a273bc8 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -200,6 +200,23 @@ T Min(T a, T b) {
   return a < b ? a : b;
 }
 
+// Returns the maximum of the two parameters according to JavaScript semantics.
+template <typename T>
+T JSMax(T x, T y) {
+  if (std::isnan(x)) return x;
+  if (std::isnan(y)) return y;
+  if (std::signbit(x) < std::signbit(y)) return x;
+  return x > y ? x : y;
+}
+
+// Returns the maximum of the two parameters according to JavaScript semantics.
+template <typename T>
+T JSMin(T x, T y) {
+  if (std::isnan(x)) return x;
+  if (std::isnan(y)) return y;
+  if (std::signbit(x) < std::signbit(y)) return y;
+  return x > y ? y : x;
+}
 
 // Returns the absolute value of its argument.
 template <typename T>