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

pkg/analyzer/lib/src/fasta/analyzer_diet_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.
 
 library fasta.analyzer_diet_listener;
 
 import 'package:analyzer/dart/ast/ast.dart' as ast show AstNode;
 
 import 'package:analyzer/dart/element/type.dart' as ast show DartType;
 
@@ skipping 13 matching lines @@
 import 'package:front_end/src/fasta/type_inference/type_inference_listener.dart'
     show TypeInferenceListener;
 
 import 'package:kernel/ast.dart' show AsyncMarker;
 
 import 'package:front_end/src/fasta/source/stack_listener.dart'
     show StackListener;
 
 import 'package:front_end/src/fasta/builder/builder.dart';
 
-import 'package:front_end/src/fasta/parser/parser.dart' show MemberKind, Parser;
+import 'package:front_end/src/fasta/parser.dart' show MemberKind, Parser;
 
 import 'package:front_end/src/scanner/token.dart' show Token;
 
 import 'package:front_end/src/fasta/source/source_library_builder.dart'
     show SourceLibraryBuilder;
 
 import 'package:front_end/src/fasta/source/diet_listener.dart'
     show DietListener;
 
 import 'package:kernel/class_hierarchy.dart' show ClassHierarchy;
@@ skipping 110 matching lines @@
   }
 
   /// Translates the given kernel types into analyzer types.
   static List<ast.DartType> _translateTypes(List<kernel.DartType> kernelTypes) {
     // For now we just translate everything to `dynamic`.
     // TODO(paulberry): implement propert translation of types.
     return new List<ast.DartType>.filled(
         kernelTypes.length, DynamicTypeImpl.instance);
   }
 }