Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/errors/cs1720.cs

@@ -0,0 +1,13 @@
+// CS1720: Expression will always cause a `System.NullReferenceException'
+// Line: 11
+// Compiler options: -warnaserror -warn:1
+
+using System;
+
+public class Tester 
+{
+    public static void Main()
+    {
+        Console.WriteLine(((object)null).ToString());
+    }
+}