Fix type errors in sort().

pkg/dev_compiler/tool/input_sdk/private/js_array.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.
 
 part of dart._interceptors;
 
 /**
  * The interceptor class for [List]. The compiler recognizes this
  * class as an interceptor, and changes references to [:this:] to
  * actually use the receiver of the method, which is generated as an extra
@@ skipping 445 matching lines @@
       if (!test(element)) return false;
       if (this.length != end) throw new ConcurrentModificationError(this);
     }
     return true;
   }
 
   Iterable<E> get reversed => new ReversedListIterable<E>(this);
 
   void sort([int compare(E a, E b)]) {
     checkMutable('sort');
-    Sort.sort(this, compare == null ? Comparable.compare : compare);
+    if (compare == null) {
+      Sort.sort(this, (a, b) => Comparable.compare(a, b));
+    } else {
+      Sort.sort(this, compare);
+    }
   }
 
   void shuffle([Random random]) {
     checkMutable('shuffle');
     if (random == null) random = new Random();
     int length = this.length;
     while (length > 1) {
       int pos = random.nextInt(length);
       length -= 1;
       var tmp = this[length];
@@ skipping 137 matching lines @@
 
     if (_index >= length) {
       _current = null;
       return false;
     }
     _current = _iterable[_index];
     _index++;
     return true;
   }
 }