Fix type-annotation and add another tests.

tests/language/lazy_static4_test.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+final x = foo(499);
+final y = foo(41) + 1;
+
+final t = bar(499);
+final u = bar(41) + 1;
+final v = bar("some string");
+
+foo(x) => x; // The return type will always be integer.

[kasperl, 2012/09/05 12:27:33]

integer -> int (twice)?

[floitsch, 2012/09/05 12:54:02]

Done.

+bar(x) => x; // The return type varies and can be integer or String.
+
+main() {
+  Expect.equals(499, x);
+  Expect.equals(42, y);
+  Expect.equals(499, t);
+  Expect.equals(42, u);
+  Expect.equals("some string", v);
+}