Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/errors/cs1648.cs

@@ -0,0 +1,15 @@
+// CS1648: Members of readonly field `C.s' cannot be modified (except in a constructor or a variable initializer)
+// Line: 13
+
+struct S {
+	public int x;
+}
+
+class C {
+	readonly S s;
+
+	public void Test ()
+        {
+		s.x = 42;
+	}
+}