Move DualPivotQuicksort from coreimpl to core as _Sort.

lib/compiler/implementation/lib/interceptors.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.
 
 #library('dart:_interceptors');
 
 #import('dart:coreimpl');
 
 add$1(var receiver, var value) {
   if (isJsArray(receiver)) {
@@ skipping 346 matching lines @@
     return Collections.every(receiver, f);
   }
 }
 
 // TODO(ngeoffray): Make it possible to have just one "sort" function ends
 // an optional parameter.
 
 sort$0(receiver) {
   if (!isJsArray(receiver)) return UNINTERCEPTED(receiver.sort());
   checkMutable(receiver, 'sort');
-  DualPivotQuicksort.sort(receiver, Comparable.compare);
+  coreSort(receiver, Comparable.compare);
 }
 
 sort$1(receiver, compare) {
   if (!isJsArray(receiver)) return UNINTERCEPTED(receiver.sort(compare));
   checkMutable(receiver, 'sort');
-  DualPivotQuicksort.sort(receiver, compare);
+  coreSort(receiver, compare);
 }
 
 isNegative(receiver) {
   if (receiver is num) {
     return (receiver == 0) ? (1 / receiver) < 0 : receiver < 0;
   } else {
     return UNINTERCEPTED(receiver.isNegative());
   }
 }
 
@@ skipping 296 matching lines @@
   } else if (isJsArray(receiver)) {
     return getOrCreateCachedRuntimeType('List');
   } else {
     return UNINTERCEPTED(receiver.runtimeType);
   }
 }
 
 // TODO(lrn): These getters should be generated automatically for all
 // intercepted methods.
 get$toString(receiver) => () => toString(receiver);