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

sdk/lib/_internal/pub_generated/lib/src/dart.dart

 // Copyright (c) 2013, 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.
 
 /// A library for compiling Dart code and manipulating analyzer parse trees.
 library pub.dart;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
 import 'package:analyzer/analyzer.dart';
 import 'package:path/path.dart' as path;
 
-import '../../../../../../pkg/compiler/lib/compiler.dart' as compiler;
-import '../../../../../../pkg/compiler/lib/src/filenames.dart' show appendSlash;
+import '../../../compiler/compiler.dart' as compiler;
+import '../../../compiler/implementation/filenames.dart' show appendSlash;
 
 import '../../asset/dart/serialize.dart';
 import 'io.dart';
 import 'log.dart' as log;
 
 /// Interface to communicate with dart2js.
 ///
 /// This is basically an amalgamation of dart2js's
 /// [compiler.CompilerInputProvider], [compiler.CompilerOutputProvider], and
 /// [compiler.DiagnosticHandler] function types so that we can provide them
@@ skipping 287 matching lines @@
       message['message'],
       packageRoot: packageRoot).then((_) => replyTo.send({
     'type': 'success'
   })).catchError((e, stack) {
     replyTo.send({
       'type': 'error',
       'error': CrossIsolateException.serialize(e, stack)
     });
   });
 }