Fix for issue r1469: DartVM appears to not GC closure reachable memory properly

tests/language/src/GCTest.dart

+// Copyright (c) 2011, 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.
+// Testing GC, issue 1469.
+
+
+main() {
+  var div;
+  for (int i = 0; i < 200; ++i) {
+    List l = new List(1000000);
+    var m  = 2;
+    div = (_) {
+      var b = l;  // Was causing OutOfMemory.
+    };
+  }
+}