Break up another large file

pkg/analyzer/lib/src/generated/element_resolver.dart

 // Copyright (c) 2014, 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 analyzer.src.generated.element_resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
+import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/ast/ast.dart'
     show
         ChildEntities,
         IdentifierImpl,
         PrefixedIdentifierImpl,
         SimpleIdentifierImpl;
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/type.dart';
+import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart';
-import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/resolver.dart';
 
 /**
  * An object used by instances of [ResolverVisitor] to resolve references within
  * the AST structure to the elements being referenced. The requirements for the
  * element resolver are:
  *
  * 1. Every [SimpleIdentifier] should be resolved to the element to which it
  *    refers. Specifically:
  *    * An identifier within the declaration of that name should resolve to the
@@ skipping 2600 matching lines @@
 
   @override
   Element get staticElement => null;
 
   @override
   dynamic/*=E*/ accept/*<E>*/(AstVisitor/*<E>*/ visitor) => null;
 
   @override
   void visitChildren(AstVisitor visitor) {}
 }