Merge kernel closure conversion into the Dart SDK

pkg/kernel/lib/type_propagation/canonicalizer.dart

 // Copyright (c) 2016, 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.
 library kernel.type_propagation.canonicalizer;
 
 import 'dart:collection';
 
 /// Generates unique consecutive integer IDs for tuples of variable length.
 class TupleCanonicalizer {
   final HashMap<List<Object>, int> _table = new HashMap<List<Object>, int>(
@@ skipping 81 matching lines @@
   }
 
   /// Associates [value] with the pair previously queried using [lookup].
   void put(T value) {
     _table[_key] = value;
   }
 
   Iterable<T> get values => _table.values;
 
   static int _bigintHash(int bigint) {
-        int x = 0x3fffffff & (bigint >> 31);
-        int y = 0x3fffffff & bigint;
+    int x = 0x3fffffff & (bigint >> 31);
+    int y = 0x3fffffff & bigint;
     int hash = 0x3fffffff & (x * 1367);
     hash = 0x3fffffff & (y * 31 + hash ^ y);
     hash = 0x3fffffff & ((x ^ y) * 31 + hash ^ y);
     return hash;
   }
 }