Custom formatter cleanup Fix case where displaying a class constructor generated unreadable huge ou…

pkg/dev_compiler/tool/input_sdk/private/js_helper.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.
 
 library dart._js_helper;
 
 import 'dart:collection';
 
 import 'dart:_foreign_helper' show
     JS,
     JS_STRING_CONCAT;
 
 import 'dart:_interceptors';
 import 'dart:_internal' show
     EfficientLength,
     MappedIterable,
     IterableElementError;
 
 import 'dart:_native_typed_data';
 
 part 'annotations.dart';
 part 'linked_hash_map.dart';
 part 'native_helper.dart';
 part 'regexp_helper.dart';
 part 'string_helper.dart';
 part 'js_rti.dart';
 
+final _identityHashCode = JS('', 'Symbol("_identityHashCode")');
+
 class _Patch {
   const _Patch();
 }
 
 const _Patch patch = const _Patch();
 
 /// Marks the internal map in dart2js, so that internal libraries can is-check
 // them.
 abstract class InternalMap<K, V> implements Map<K, V> {}
 
@@ skipping 12 matching lines @@
   /// Please don't add complicated code to this method, as it will impact
   /// start-up performance.
   static void initializeStatics(int id) {
     // Benchmarking shows significant performance improvements if this is a
     // fixed value.
     mirrorFunctionCacheName += '_$id';
     mirrorInvokeCacheName += '_$id';
   }
 
   static int objectHashCode(object) {
-    int hash = JS('int|Null', r'#.$identityHash', object);
+    int hash = JS('int|Null', r'#[#]', object, _identityHashCode);
     if (hash == null) {
       hash = JS('int', '(Math.random() * 0x3fffffff) | 0');
-      JS('void', r'#.$identityHash = #', object, hash);
+      JS('void', r'#[#] = #', object, _identityHashCode, hash);
     }
     return JS('int', '#', hash);
   }
 
   @NoInline()
   static int _parseIntError(String source, int handleError(String source)) {
     if (handleError == null) throw new FormatException(source);
     return handleError(source);
   }
 
@@ skipping 831 matching lines @@
   // we have no way of telling the compiler yet, so it will generate an extra
   // layer of indirection that wraps the SyncIterator.
   _jsIterator() => JS('', '#(...#)', _generator, _args);
 
   Iterator<E> get iterator => new SyncIterator<E>(_jsIterator());
 }
 
 class BooleanConversionAssertionError extends AssertionError {
   toString() => 'Failed assertion: boolean expression must not be null';
 }