Support default constructors in analyzer2dart.

pkg/analyzer2dart/test/end2end_data.dart

 // Copyright (c) 2014, 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.
 
 /// Test data for the end2end test.
 library test.end2end.data;
 
 import 'test_helper.dart';
 
 class TestSpec extends TestSpecBase {
@@ skipping 802 matching lines @@
     return 0;
   } : () {
     return 1;
   })();
 }
 '''),
   ]),
 
   const Group('Constructors', const <TestSpec>[
     const TestSpec('''
+class C {}
+main() {
+  return new C();
+}
+'''),
+
+    const TestSpec('''
 class C {
   C() {}
 }
 main() {
   return new C();
 }
 '''),
+
+    const TestSpec('''
+class B {}
+class C extends B {
+  C() {}
+}
+main() {
+  return new C();
+}
+'''),
+
+    const TestSpec('''
+class B {
+  B() {}
+}
+class C extends B {}
+main() {
+  return new C();
+}
+'''),
   ]),
 
   const Group('Instance method', const <TestSpec>[
     const TestSpec('''
 class C {
   C() {}
   foo() {}
 }
 main() {
   return new C().foo();
 }
 '''),
 ]),
 ];