Hide collection-dev library.

tests/corelib/hidden_library2_test.dart

+// Copyright (c) 2013, 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.
+// Test that the internal hidden library doesn't make problems with taking
+// stack-traces.
+
+main() {
+  print(['x'].where((_) {
+    // We actually don't really care for the successful case. We just want to
+    // make sure that the test doesn't crash when it is negative.
+    throw 'fisk';  /// 1: runtime error
+    return true;
+  }));
+}