Include uriToSource from dill-based libraries in output

pkg/front_end/lib/src/fasta/kernel/kernel_target.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.kernel_target;
 
 import 'dart:async' show Future;
 
 import 'dart:io' show File;
 
@@ skipping 353 matching lines @@
     return link(<Library>[library.library]);
   }
 
   /// Creates a program by combining [libraries] with the libraries of
   /// `dillTarget.loader.program`.
   Program link(List<Library> libraries, {CanonicalName nameRoot}) {
     Map<String, Source> uriToSource =
         new Map<String, Source>.from(this.uriToSource);
 
     libraries.addAll(dillTarget.loader.libraries);
-    // TODO(scheglov) Should we also somehow update `uriToSource`?
-//    uriToSource.addAll(binary.uriToSource);
+    uriToSource.addAll(dillTarget.loader.uriToSource);
 
     // TODO(ahe): Remove this line. Kernel seems to generate a default line map
     // that used when there's no fileUri on an element. Instead, ensure all
     // elements have a fileUri.
     uriToSource[""] = new Source(<int>[0], const <int>[]);
     Program program = new Program(
         nameRoot: nameRoot, libraries: libraries, uriToSource: uriToSource);
     if (loader.first != null) {
       // TODO(sigmund): do only for full program
       Builder builder = loader.first.lookup("main", -1, null);
@@ skipping 314 matching lines @@
   }
   for (Constructor constructor in superclass.constructors) {
     if (constructor.name.name.isEmpty) {
       return constructor.function.requiredParameterCount == 0
           ? constructor
           : null;
     }
   }
   return null;
 }