Import rasta tests.

pkg/fasta/test/rasta/issue_000031.dart

Index: pkg/fasta/test/rasta/issue_000031.dart
diff --git a/pkg/fasta/test/rasta/issue_000031.dart b/pkg/fasta/test/rasta/issue_000031.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9f6f91a84e441d7d531229f5f32164fad4ecaef1
--- /dev/null
+++ b/pkg/fasta/test/rasta/issue_000031.dart
@@ -0,0 +1,9 @@
+// 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.md file.
+
+import 'dart:math' as math;
+
+main() {
+  math..toString();
+}