Move parser helper classes to own files and clean them up.

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

Index: pkg/compiler/lib/src/parser/node_listener.dart
diff --git a/pkg/compiler/lib/src/parser/node_listener.dart b/pkg/compiler/lib/src/parser/node_listener.dart
index c44cd7d81694af861aacc9492f79205e08a30cf1..342bd4d9a6f0a8395e113317cd15ca47ecad3e7c 100644
--- a/pkg/compiler/lib/src/parser/node_listener.dart
+++ b/pkg/compiler/lib/src/parser/node_listener.dart
@@ -4,10 +4,8 @@
 
 library dart2js.parser.node_listener;
 
-import 'package:front_end/src/fasta/parser/parser.dart'
-    show FormalParameterType, MemberKind;
-import 'package:front_end/src/fasta/parser/identifier_context.dart'
-    show IdentifierContext;
+import 'package:front_end/src/fasta/parser.dart'
+    show FormalParameterKind, IdentifierContext, MemberKind;
 import 'package:front_end/src/fasta/scanner.dart' show Token;
 import 'package:front_end/src/scanner/token.dart' show TokenType;
 
@@ -17,7 +15,7 @@ import '../tree/tree.dart';
 import '../util/util.dart' show Link;
 import 'element_listener.dart' show ElementListener, ScannerOptions;
 
-import 'package:front_end/src/fasta/parser/parser.dart' as fasta show Assert;
+import 'package:front_end/src/fasta/parser.dart' as fasta show Assert;
 
 class NodeListener extends ElementListener {
   NodeListener(ScannerOptions scannerOptions, DiagnosticReporter reporter,
@@ -232,7 +230,7 @@ class NodeListener extends ElementListener {
 
   @override
   void endFormalParameter(Token thisKeyword, Token nameToken,
-      FormalParameterType kind, MemberKind memberKind) {
+      FormalParameterKind kind, MemberKind memberKind) {
     Expression name = popNode();
     if (thisKeyword != null) {
       Identifier thisIdentifier = new Identifier(thisKeyword);