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

tests/compiler/dart2js/members_test.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 members_test;
 
 import 'package:expect/expect.dart';
 import "package:async_helper/async_helper.dart";
 import 'type_test_helper.dart';
-import 'package:compiler/src/dart_types.dart';
-import "package:compiler/src/elements/elements.dart"
+import 'package:compiler/implementation/dart_types.dart';
+import "package:compiler/implementation/elements/elements.dart"
        show Element, ClassElement, MemberSignature, Name, PublicName,
             DeclaredMember, Member;
-import "package:compiler/src/resolution/class_members.dart"
+import "package:compiler/implementation/resolution/class_members.dart"
   show DeclaredMember, ErroneousMember, SyntheticMember;
 
 void main() {
   testClassMembers();
   testInterfaceMembers();
   testClassVsInterfaceMembers();
   testMixinMembers();
   testMixinMembersWithoutImplements();
 }
 
@@ skipping 675 matching lines @@
 
     InterfaceType A = env['A'];
     InterfaceType B = env['B'];
     InterfaceType C = env['C'];
 
     checkMember(C, 'm', checkType: NO_CLASS_MEMBER,
                 inheritedFrom: A,
                 functionType: env.functionType(dynamic_ , []));
   }));
 }