Add contextual information about identifiers to the parser listener API.

pkg/compiler/lib/src/parser/element_listener.dart

Index: pkg/compiler/lib/src/parser/element_listener.dart
diff --git a/pkg/compiler/lib/src/parser/element_listener.dart b/pkg/compiler/lib/src/parser/element_listener.dart
index 279f9d67577e7b2f7b0d58fb73a7190740c7c763..cc9c2e3e708d411a180c52ace9e83c69b3fe981e 100644
--- a/pkg/compiler/lib/src/parser/element_listener.dart
+++ b/pkg/compiler/lib/src/parser/element_listener.dart
@@ -31,6 +31,8 @@ import '../tree/tree.dart';
 import '../util/util.dart' show Link, LinkBuilder;
 import 'package:front_end/src/fasta/parser.dart'
     show ErrorKind, Listener, ParserError, optional;
+import 'package:front_end/src/fasta/parser/identifier_context.dart'
+    show IdentifierContext;
 import 'partial_elements.dart'
     show
         PartialClassElement,
@@ -384,7 +386,7 @@ class ElementListener extends Listener {
   }
 
   @override
-  void handleIdentifier(Token token) {
+  void handleIdentifier(Token token, IdentifierContext context) {
     pushNode(new Identifier(token));
   }