Imported Upstream version 3.8.0

Former-commit-id: 6a76a29bd07d86e57c6c8da45c65ed5447d38a61

mcs/errors/cs0151-3.cs

@@ -0,0 +1,19 @@
+// CS0151: A switch expression of type `X?' cannot be converted to an integral type, bool, char, string, enum or nullable type
+// Line: 15
+
+struct X 
+{
+    public static implicit operator int (X x)
+    {
+        return 1;
+    }
+
+	static void Main ()
+	{
+		X? x = null;
+		switch (x) {
+		default:
+			break;
+		}
+	}
+}