Imported Upstream version 5.12.0.220

Former-commit-id: c477e03582759447177c6d4bf412cd2355aad476

mcs/tests/test-default-01.cs

@@ -41,7 +41,11 @@ static class X
 	static System.Func<int> M4 ()
 	{
 		return () => default;
-	} 
+	}
+
+	static void Foo (II a = default (II), II b = default, II c = (II) null)
+	{
+	}
 }
 /*
 enum E
@@ -49,4 +53,10 @@ enum E
 	A = default,
 	B = default + 1
 }
-*/
+*/
+
+
+interface II
+{
+
+}