Some use of the new @static-clean and /// annotations in shared tests

tests/language/src/DynamicFieldTest.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.
 //
 // Test that ensures that fields can be accessed dynamically.
 
 class A extends C {
   var a;
   var b;
 }
 
 class C {
   foo() {
-    print(a);
-    return a;
+    print(a); /// static type error
+    return a; /// static type error
   }
   bar() {
-    print(b.a);
-    return b.a;
+    print(b.a); /// static type error
+    return b.a; /// static type error
   }
 }
 
 main() {
   var a = new A();
   a.a = 1;
   a.b = a;
   Expect.equals(1, a.foo());
   Expect.equals(1, a.bar());
 }