Handle top-level getters and setters in parts.

pkg/front_end/test/fasta/top_level_accessors_part.dart

Index: pkg/front_end/test/fasta/top_level_accessors_part.dart
diff --git a/pkg/front_end/test/fasta/top_level_accessors_part.dart b/pkg/front_end/test/fasta/top_level_accessors_part.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6aeed084ba637468d8796833f1ad7ccc12746453
--- /dev/null
+++ b/pkg/front_end/test/fasta/top_level_accessors_part.dart
@@ -0,0 +1,16 @@
+// Copyright (c) 2017, 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.
+
+part of top_level_accessors;
+
+void set exitCode(int code) {
+  print(code);
+}
+
+int get exitCode => 0;
+
+main() {
+  exitCode = 42;
+  print(exitCode);
+}