Imported Upstream version 4.2.0.179

Former-commit-id: 4610231f55806d2a05ed69e5ff3faa7336cc1479

mcs/tests/dtest-optional-02.cs

@@ -0,0 +1,18 @@
+using System.Runtime.InteropServices;
+
+public class Test
+{
+	public static object Foo ([Optional, DefaultParameterValue (1)] dynamic i)
+	{
+		return i;
+	}
+
+	public static int Main ()
+	{
+		var res = (int) Foo ();
+		if (res != 1)
+			return 1;
+
+		return 0;
+	}
+}