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

tests/compiler/dart2js/mirrors_test.dart

 // Copyright (c) 2012, 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.
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
-import 'package:compiler/src/mirrors/source_mirrors.dart';
-import 'package:compiler/src/mirrors/mirrors_util.dart';
-import 'package:compiler/src/mirrors/analyze.dart';
-import 'package:compiler/src/filenames.dart'
+import 'package:compiler/implementation/mirrors/source_mirrors.dart';
+import 'package:compiler/implementation/mirrors/mirrors_util.dart';
+import 'package:compiler/implementation/mirrors/analyze.dart';
+import 'package:compiler/implementation/filenames.dart'
        show currentDirectory;
-import 'package:compiler/src/source_file_provider.dart';
+import 'package:compiler/implementation/source_file_provider.dart';
 
 import 'dart:io';
 
 final Uri DART_MIRRORS_URI = new Uri(scheme: 'dart', path: 'mirrors');
 
 int count(Iterable iterable) {
   var count = 0;
   for (var element in iterable) {
     count++;
   }
@@ skipping 963 matching lines @@
   Expect.isTrue(privateFactoryConstructor.isPrivate);
   Expect.isFalse(privateFactoryConstructor.isConstConstructor);
   Expect.isFalse(privateFactoryConstructor.isRedirectingConstructor);
   Expect.isFalse(privateFactoryConstructor.isGenerativeConstructor);
   Expect.isTrue(privateFactoryConstructor.isFactoryConstructor);
 
   var metadata = privateClass.metadata;
   Expect.isNotNull(metadata);
   Expect.equals(0, metadata.length);
 }