Use identical in token operators.

pkg/compiler/lib/src/serialization/serialization.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.
 
 library dart2js.serialization;
 
+import 'package:front_end/src/fasta/scanner/precedence.dart' show
+    PrecedenceInfo;
+
 import '../common.dart';
 import '../common/resolution.dart';
 import '../constants/expressions.dart';
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../library_loader.dart' show LibraryProvider;
 import '../util/enumset.dart';
 import 'constant_serialization.dart';
 import 'element_serialization.dart';
 import 'json_serializer.dart';
 import 'keys.dart';
 import 'type_serialization.dart';
 import 'values.dart';
 
 export 'task.dart' show LibraryDeserializer;
 
+final Map<String, String> canonicalNames = computeCanonicalNames();
+
+Map<String, String> computeCanonicalNames() {
+  Map<String, String> result = <String, String>{};
+  for (PrecedenceInfo info in PrecedenceInfo.all) {
+    result[info.value] = info.value;
+  }
+  return result;
+}
+
 /// An object that supports the encoding an [ObjectValue] for serialization.
 ///
 /// The [ObjectEncoder] ensures that nominality and circularities of
 /// non-primitive values like [Element], [ResolutionDartType] and
 /// [ConstantExpression] are handled.
 class ObjectEncoder extends AbstractEncoder<Key> {
   /// Creates an [ObjectEncoder] in the scope of [serializer] that uses [map]
   /// as its internal storage.
   ObjectEncoder(Serializer serializer, Map<dynamic, Value> map)
       : super(serializer, map);
@@ skipping 431 matching lines @@
   /// If no value is associated with [key], then if [isOptional] is `true`,
   /// [defaultValue] is returned, otherwise an exception is thrown.
   String getString(K key, {bool isOptional: false, String defaultValue}) {
     String value = _map[_getKeyValue(key)];
     if (value == null) {
       if (isOptional || defaultValue != null) {
         return defaultValue;
       }
       throw new StateError("String value '$key' not found in $_map.");
     }
-    return value;
+    return canonicalNames[value] ?? value;
   }
 
   /// Returns the list of [String] values associated with [key] in the decoded
   /// object.
   ///
   /// If no value is associated with [key], then if [isOptional] is `true`,
   /// and empty [List] is returned, otherwise an exception is thrown.
   List<String> getStrings(K key, {bool isOptional: false}) {
     List list = _map[_getKeyValue(key)];
     if (list == null) {
@@ skipping 654 matching lines @@
 
   /// Returns the value used to store [key] as a property in the encoding an
   /// [ObjectValue].
   ///
   /// Different encodings have different restrictions and capabilities as how
   /// to store a [Key] value. For instance: A JSON encoding needs to convert
   /// [Key] to a [String] to store it in a JSON object; a Dart encoding can
   /// choose to store a [Key] as an [int] or as the [Key] itself.
   getObjectPropertyValue(Key key);
 }