Correctly resolve package parts.

pkg/front_end/lib/src/fasta/translate_uri.dart

 // Copyright (c) 2016, 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 fasta.translate_uri;
 
 import 'dart:async' show
     Future;
 
 import 'dart:io' show
@@ skipping 49 matching lines @@
       "js_util": sdk.resolve("lib/js_util/dartium/js_util_dartium.dart"),
       "math": sdk.resolve("lib/math/math.dart"),
       "mirrors": sdk.resolve("lib/mirrors/mirrors.dart"),
       "nativewrappers": sdk.resolve("lib/html/dartium/nativewrappers.dart"),
       "typed_data": sdk.resolve("lib/typed_data/typed_data.dart"),
       "svg": sdk.resolve("lib/svg/dartium/svg_dartium.dart"),
       "web_audio": sdk.resolve("lib/web_audio/dartium/web_audio_dartium.dart"),
       "web_gl": sdk.resolve("lib/web_gl/dartium/web_gl_dartium.dart"),
       "web_sql": sdk.resolve("lib/web_sql/dartium/web_sql_dartium.dart"),
       "_internal": sdk.resolve("lib/internal/internal.dart"),
+      "profiler": sdk.resolve("lib/profiler/profiler.dart"),
+      "vmservice_io": sdk.resolve("lib/vmservice_io/vmservice_io.dart"),
+      "_vmservice": sdk.resolve("lib/vmservice/vmservice.dart"),
+      "_builtin": sdk.resolve("lib/_builtin/_builtin.dart"),
     };
     uri ??= Uri.base.resolve(".packages");
     File file = new File.fromUri(uri);
     List<int> bytes = await file.readAsBytes();
     Map<String, Uri> packages = packages_file.parse(bytes, uri);
     return new TranslateUri(packages, dartLibraries);
   }
 }