Import rasta tests.

pkg/fasta/test/rasta/issue_000042.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.md file.
+
+main() {
+  for (var x, y in []) {}
+  L: { continue L; }
+  L: if (true) { continue L; }
+  L: switch (1) {
+    case 1:
+      continue L;
+    case 2:
+      break L;
+  }
+  try {
+  } on NoSuchMethodError {
+  }
+}