Add Fasta tests.

pkg/fasta/test/classes.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 file.
+
+class A {
+  final int x;
+  final int y;
+  A(this.y) : x = 42;
+  method() {
+    print("A.method x: $x y: $y");
+    print(this);
+    print(this.runtimeType);
+  }
+}
+
+class B extends A {
+  B(x) : super(x);
+  method() {
+    print("B.method x: $x y: $y");
+    super.method();
+  }
+}
+
+main() {
+  A a = new A(87);
+  B b = new B(117);
+  a.method();
+  b.method();
+}