Move parser and token related libraries into their own subfolder.

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

 // Copyright (c) 2011, 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 dart2js.parser.classes;
 
 import '../compiler.dart' show
     Compiler;
 import '../diagnostics/diagnostic_listener.dart' show
     DiagnosticListener;
 import '../diagnostics/messages.dart' show
     MessageKind;
 import '../diagnostics/invariant.dart' show
     invariant;
 import '../elements/elements.dart' show
     CompilationUnitElement,
     Element,
     ElementKind,
     Elements,
     MetadataAnnotation,
     STATE_NOT_STARTED,
     STATE_DONE;
 import '../elements/modelx.dart' show
     ClassElementX,
     ElementX,
     FieldElementX,
     VariableList;
 import '../elements/visitor.dart' show
     ElementVisitor;
+import '../tokens/token.dart' show
+    Token;
 import '../tree/tree.dart';
 import '../util/util.dart' show
     Link;
 
 import 'listener.dart' show
     Listener,
     NodeListener,
     ParserError,
     PartialConstructorElement,
     PartialElement,
     PartialFunctionElement,
     PartialMetadataAnnotation;
 import 'parser.dart' show
     Parser;
 import 'partial_parser.dart' show
     PartialParser;
-import 'token.dart' show
-    Token;
 
 class ClassElementParser extends PartialParser {
   ClassElementParser(Listener listener) : super(listener);
 
   Token parseClassBody(Token token) => fullParseClassBody(token);
 }
 
 class PartialClassElement extends ClassElementX with PartialElement {
   ClassNode cachedNode;
 
@@ skipping 219 matching lines @@
 
   void endMetadata(Token beginToken, Token periodBeforeName, Token endToken) {
     popNode(); // Discard arguments.
     if (periodBeforeName != null) {
       popNode(); // Discard name.
     }
     popNode(); // Discard node (Send or Identifier).
     pushMetadata(new PartialMetadataAnnotation(beginToken, endToken));
   }
 }