Adding package:code_transformers for unifying common transformers code

pkg/code_transformers/lib/resolver.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.
 
-class A {
-  static var a;
-  var b;
-}
+/// Tools for working with resolved ASTs from Barback transformers.
+library code_transformers.resolver;
 
-class B extends A {
-
-}
-
-class C extends B {
-  var a; /// 01: static type warning
-  static var b; /// 02: compile-time error
-}
-
-void main() {
-  new C();
-}
+export 'src/resolver_transformer.dart';
+export 'src/resolver.dart';
+export 'src/dart_sdk.dart';