Intl test spawning processes must specify the encoding for stdout

pkg/intl/test/message_extraction/message_extraction_test.dart

Index: pkg/intl/test/message_extraction/message_extraction_test.dart
diff --git a/pkg/intl/test/message_extraction/message_extraction_test.dart b/pkg/intl/test/message_extraction/message_extraction_test.dart
index ff45d3e12e73b0be52e5a2ae6398b07fbd830c17..0b00fdb99f8a8fb3d6137a3686ee3f7ae815eb6b 100644
--- a/pkg/intl/test/message_extraction/message_extraction_test.dart
+++ b/pkg/intl/test/message_extraction/message_extraction_test.dart
@@ -97,6 +97,9 @@ Future<ProcessResult> run(ProcessResult previousResult, List<String> filenames)
       ..add(filesInTheRightDirectory.first)
       ..addAll(["--output-dir=${dir()}"])
       ..addAll(filesInTheRightDirectory.skip(1));
+  var options = new ProcessOptions()
+      ..stdoutEncoding=Encoding.UTF_8
+      ..stderrEncoding=Encoding.UTF_8;
   var result = Process.run(dart, args);
   return result;
 }