Implement JS version of LinkedHashSet and move the various HashTable implementations to the VM coll…

sdk/lib/collection/hash_map.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.
 
 part of dart.collection;
 
-class _HashMapTable<K, V> extends _HashTable<K> {
-  static const int _INITIAL_CAPACITY = 8;
-  static const int _VALUE_INDEX = 1;
-
-  _HashMapTable() : super(_INITIAL_CAPACITY);
-
-  int get _entrySize => 2;
-
-  V _value(int offset) => _table[offset + _VALUE_INDEX];
-  void _setValue(int offset, V value) { _table[offset + _VALUE_INDEX] = value; }
-
-  _copyEntry(List fromTable, int fromOffset, int toOffset) {
-    _table[toOffset + _VALUE_INDEX] = fromTable[fromOffset + _VALUE_INDEX];
-  }
-}
-
 class HashMap<K, V> implements Map<K, V> {
   external HashMap();
 
   factory HashMap.from(Map<K, V> other) {
     return new HashMap<K, V>()..addAll(other);
   }
 
   external int get length;
   external bool get isEmpty;
 
@@ skipping 10 matching lines @@
 
   external V putIfAbsent(K key, V ifAbsent());
 
   external V remove(K key);
   external void clear();
 
   external void forEach(void action(K key, V value));
 
   String toString() => Maps.mapToString(this);
 }