Revert "Move dart2js from sdk/lib/_internal/compiler to pkg/compiler"

pkg/analyzer2dart/lib/src/element_converter.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.
 
 /// Convertion of elements between the analyzer element model and the dart2js
 /// element model.
 
 library analyzer2dart.element_converter;
 
-import 'package:compiler/src/elements/elements.dart' as dart2js;
-import 'package:compiler/src/elements/modelx.dart' as modelx;
-import 'package:compiler/src/util/util.dart' as util;
-import 'package:compiler/src/dart_types.dart' as dart2js;
+import 'package:compiler/implementation/elements/elements.dart' as dart2js;
+import 'package:compiler/implementation/elements/modelx.dart' as modelx;
+import 'package:compiler/implementation/util/util.dart' as util;
+import 'package:compiler/implementation/dart_types.dart' as dart2js;
 import 'package:analyzer/src/generated/element.dart' as analyzer;
 
 part 'modely.dart';
 
 class ElementConverter {
   /// Map from analyzer elements to their equivalent dart2js elements.
   Map<analyzer.Element, dart2js.Element> conversionMap =
       <analyzer.Element, dart2js.Element>{};
 
   /// Map from dart2js elements to their equivalent analyzer elements.
@@ skipping 129 matching lines @@
       analyzer.LocalVariableElement input) {
     return new LocalVariableElementY(converter, input);
   }
 
   @override
   dart2js.ConstructorElement visitConstructorElement(
       analyzer.ConstructorElement input) {
     return new ConstructorElementY(converter, input);
   }
 }