Support roundevenf/roundeven

lib/std/math_builtin.c3

@@ -0,0 +1,13 @@
+module std::math;
+
+fn float __roundevenf(float f) @extname("roundevenf") @weak
+{
+	// Slow implementation
+	return round(f / 2) * 2;
+}
+
+fn double __roundeven(double d) @extname("roundeven") @weak
+{
+	// Slow implementation
+	return round(d / 2) * 2;
+}