Use kernel transformation and VmTarget.

pkg/front_end/lib/src/fasta/target_implementation.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.target_implementation;
 
+import 'package:kernel/target/vm.dart' show
+    VmTarget;
+
 import 'builder/builder.dart' show
     Builder,
     ClassBuilder,
     LibraryBuilder;
 
 import 'loader.dart' show
     Loader;
 
 import 'target.dart' show
     Target;
@@ skipping 40 matching lines @@
   }
 
   /// Returns a reference to the constructor used for creating `native`
   /// annotations. The constructor is expected to accept a single argument of
   /// type String, which is the name of the native method.
   Builder getNativeAnnotation(Loader loader) {
     if (cachedNativeAnnotation != null) return cachedNativeAnnotation;
     LibraryBuilder internal = loader.read(Uri.parse("dart:_internal"));
     return cachedNativeAnnotation = internal.getConstructor("ExternalName");
   }
+
+  void loadExtraRequiredLibraries(Loader loader) {
+    for (String uri in new VmTarget(null).extraRequiredLibraries) {
+      loader.read(Uri.parse(uri));
+    }
+  }
 }