Remove public int.is64Bit.

runtime/lib/compact_hash.dart

 // Copyright (c) 2015, 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.
 
 import 'dart:typed_data';
+import 'dart:_internal' as internal;
 
 // Hash table with open addressing that separates the index from keys/values.
 abstract class _HashBase {
   // Each occupied entry in _index is a fixed-size integer that encodes a pair:
   //   [ hash pattern for key | index of entry in _data ]
   // The hash pattern is based on hashCode, but is guaranteed to be non-zero.
   // The length of _index is always a power of two, and there is always at
   // least one unoccupied entry.
   Uint32List _index;
 
   // The number of bits used for each component is determined by table size.
   // The length of _index is twice the number of entries in _data, and both
   // are doubled when _data is full. Thus, _index will have a max load factor
   // of 1/2, which enables one more bit to be used for the hash.
   // TODO(koda): Consider growing _data by factor sqrt(2), twice as often.
   static const int _INITIAL_INDEX_BITS = 3;
   static const int _INITIAL_INDEX_SIZE = 1 << (_INITIAL_INDEX_BITS + 1);
 
   // Unused and deleted entries are marked by 0 and 1, respectively.
   static const int _UNUSED_PAIR = 0;
   static const int _DELETED_PAIR = 1;
 
   // Cached in-place mask for the hash pattern component. On 32-bit, the top
   // bits are wasted to avoid Mint allocation.
   // TODO(koda): Reclaim the bits by making the compiler treat hash patterns
   // as unsigned words.
-  int _hashMask = int.is64Bit() ?
+  int _hashMask = internal.is64Bit ?
       (1 << (32 - _INITIAL_INDEX_BITS)) - 1 :
       (1 << (30 - _INITIAL_INDEX_BITS)) - 1;
 
   static int _hashPattern(int fullHash, int hashMask, int size) {
     final int maskedHash = fullHash & hashMask;
     // TODO(koda): Consider keeping bit length and use left shift.
     return (maskedHash == 0) ? (size >> 1) : maskedHash * (size >> 1);
   }
 
   // Linear probing.
@@ skipping 483 matching lines @@
   E lookup(Object o) => _validKey(o) ? super.lookup(o) : null;
   bool remove(Object o) => _validKey(o) ? super.remove(o) : false;
 
   _CompactLinkedCustomHashSet(this._equality, this._hasher, validKey)
       : _validKey = (validKey != null) ? validKey : new _TypeTest<E>().test;
 
   Set<E> toSet() =>
       new _CompactLinkedCustomHashSet<E>(_equality, _hasher, _validKey)
           ..addAll(this);
 }