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

pkg/analyzer/test/generated/parser_fasta_listener.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/ast/token.dart' as analyzer;
 import 'package:analyzer/src/generated/parser.dart' as analyzer;
 import 'package:front_end/src/fasta/fasta_codes.dart';
 import 'package:front_end/src/fasta/parser/identifier_context.dart'
     show IdentifierContext;
-import 'package:front_end/src/fasta/parser/listener.dart' as fasta;
-import 'package:front_end/src/fasta/parser/parser.dart' as fasta;
+import 'package:front_end/src/fasta/parser.dart' as fasta;
 import 'package:front_end/src/fasta/scanner/token.dart' as fasta;
 import 'package:front_end/src/fasta/util/link.dart';
 import 'package:front_end/src/scanner/token.dart';
 import 'package:test/test.dart';
 
 /**
  * Proxy implementation of the fasta parser listener that
  * asserts begin/end pairs of events and forwards all events
  * to the specified listener.
  */
@@ skipping 738 matching lines @@
   }
 
   @override
   void endForStatementBody(analyzer.Token token) {
     _end('ForStatementBody');
     listener.endForStatementBody(token);
   }
 
   @override
   void endFormalParameter(analyzer.Token thisKeyword, analyzer.Token nameToken,
-      fasta.FormalParameterType kind, fasta.MemberKind memberKind) {
+      fasta.FormalParameterKind kind, fasta.MemberKind memberKind) {
     _end('FormalParameter');
     listener.endFormalParameter(thisKeyword, nameToken, kind, memberKind);
   }
 
   @override
   void endFormalParameters(int count, analyzer.Token beginToken,
       analyzer.Token endToken, fasta.MemberKind kind) {
     _end('FormalParameters');
     listener.endFormalParameters(count, beginToken, endToken, kind);
   }
@@ skipping 781 matching lines @@
   @override
   set suppressParseErrors(bool value) {
     listener.suppressParseErrors = value;
     // TODO(danrubel): implement suppressParseErrors
   }
 
   // TODO(danrubel): implement uri
   @override
   Uri get uri => listener.uri;
 }