Manually check if a constructor has no body in the backend: either ends with ';', or has not statem…

frog/tests/leg/no_constructor_body_test.dart

+// Copyright (c) 2012, 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.
+
+#import("compiler_helper.dart");
+
+final String TEST = @"""
+class A {
+  A.foo() {}
+  A();
+}
+main() {
+  new A();
+  new A.foo();
+}
+""";
+
+main() {
+  String generated = compileAll(TEST);
+  Expect.isTrue(generated.contains(
+      'Isolate.\$defineClass("A", "Object", [], {\n});'));
+}