Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/test-439.cs

@@ -0,0 +1,23 @@
+using System;
+public struct LayerMask
+{
+	private ushort mask;
+	public static implicit operator int (LayerMask mask) { return (int)mask.mask; }
+	public static implicit operator LayerMask (int intVal) 
+	{ 
+		LayerMask mask;
+		mask.mask = unchecked ((ushort)intVal);
+		return mask;
+	}
+}
+
+class Test
+{
+	static private LayerMask test;
+	static public void Main ()
+	{
+		LayerMask a = ~test;
+		if (a != 0xFFFF) // LayerMask is an ushort internally
+			throw new Exception ("");
+	}
+}