unfork DDC's copy of most SDK libraries

pkg/dev_compiler/tool/input_sdk/lib/collection/collection.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.
-
-/**
- * Classes and utilities that supplement the collection support in dart:core.
- * 
- * To use this library in your code:
- *
- *     import 'dart:collection';
- */
-library dart.collection;
-
-import 'dart:_internal';
-import 'dart:math' show Random;  // Used by ListMixin.shuffle.
-
-part 'collections.dart';
-part 'hash_map.dart';
-part 'hash_set.dart';
-part 'iterable.dart';
-part 'iterator.dart';
-part 'linked_hash_map.dart';
-part 'linked_hash_set.dart';
-part 'linked_list.dart';
-part 'list.dart';
-part 'maps.dart';
-part 'queue.dart';
-part 'set.dart';
-part 'splay_tree.dart';