Support closures inside initializers.

tests/language/closure_in_initializer2_test.dart

Index: tests/language/closure_in_initializer2_test.dart
===================================================================
--- tests/language/closure_in_initializer2_test.dart	(revision 0)
+++ tests/language/closure_in_initializer2_test.dart	(revision 0)
@@ -0,0 +1,21 @@
+// 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.
+
+class S {
+  S() {
+    Expect.equals(2, this.f());
+  }
+}
+
+class A extends S {
+  var f;
+  A(a) : f = (() => ++a) {
+    Expect.equals(a, 2);
+  }
+}
+
+main() {
+  var a = new A(1);
+  Expect.equals(a.f(), 3);
+}