Import rasta tests.

pkg/fasta/test/rasta/issue_000044.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.
+
+// Parse error: but the parser should recover and create something that looks
+// like `a b(c) => d`.
+a b(c) = d;
+
+class C {
+  // Good constructor.
+  const C.constant();
+
+  // Bad constructor: missing factory keyword (and additional formals).
+  C.missingFactoryKeyword() = C.constant;
+
+  // Good redirecting const factory constructor.
+  const factory C.good() = C.constant;
+
+  // Parse error, the parser should recover and create a redirecting factory
+  // constructor body.
+  C notEvenAConstructor(a) = h;
+}
+
+main() {
+  C c = null;
+  print(const C.constant());
+  print(const C.missingFactoryKeyword());
+  print(const C.good());
+  print(new C.constant().notEvenAConstructor(null));
+}