Add contextual information about identifiers to the parser listener API.

pkg/front_end/lib/src/fasta/source/stack_listener.dart

Index: pkg/front_end/lib/src/fasta/source/stack_listener.dart
diff --git a/pkg/front_end/lib/src/fasta/source/stack_listener.dart b/pkg/front_end/lib/src/fasta/source/stack_listener.dart
index 23d915588b113e03b5131915b7d25088306c64d8..9293597f37904b4ddd72cbbea7703ce374f9ff34 100644
--- a/pkg/front_end/lib/src/fasta/source/stack_listener.dart
+++ b/pkg/front_end/lib/src/fasta/source/stack_listener.dart
@@ -8,6 +8,9 @@ import 'dart:collection' show Queue;
 
 import 'package:front_end/src/fasta/parser.dart' show ErrorKind, Listener;
 
+import 'package:front_end/src/fasta/parser/identifier_context.dart'
+    show IdentifierContext;
+
 import 'package:front_end/src/fasta/scanner.dart' show BeginGroupToken, Token;
 
 import 'package:kernel/ast.dart' show AsyncMarker;
@@ -113,7 +116,7 @@ abstract class StackListener extends Listener {
   }
 
   @override
-  void handleIdentifier(Token token) {
+  void handleIdentifier(Token token, IdentifierContext context) {
     debugEvent("handleIdentifier");
     push(token.value);
   }