Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/errors/cs1623.cs

@@ -0,0 +1,19 @@
+// CS1623: Iterators cannot have ref or out parameters
+// Line: 8
+using System;
+using System.Collections;
+
+class X
+{
+	public static IEnumerable Test (ref int a)
+	{
+		yield return 0;
+        }
+
+	static void Main ()
+	{
+		int i = 3;
+		IEnumerable a = Test (ref i);
+		Console.WriteLine (a);
+	}
+}