fixes #168, dart:js implementation with a test

tool/input_sdk/private/foreign_helper.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.
 
 library dart._foreign_helper;
 
 /**
  * Emits a JavaScript code fragment parameterized by arguments.
  *
  * Hash characters `#` in the [codeTemplate] are replaced in left-to-right order
@@ skipping 109 matching lines @@
   /// finishIsolateConstructorFunction in emitter.dart.
   get isolateStatics;
 }
 
 /**
  * Invokes [function] in the context of [isolate].
  */
 JS_CALL_IN_ISOLATE(isolate, Function function) {}
 
 /**
- * Converts the Dart closure [function] into a JavaScript closure.
- *
- * Warning: This is no different from [RAW_DART_FUNCTION_REF] which means care
- * must be taken to store the current isolate.
- */
-DART_CLOSURE_TO_JS(Function function) {}
-
-/**
- * Returns a raw reference to the JavaScript function which implements
- * [function].
- *
- * Warning: this is dangerous, you should probably use
- * [DART_CLOSURE_TO_JS] instead. The returned object is not a valid
- * Dart closure, does not store the isolate context or arity.
- *
- * A valid example of where this can be used is as the second argument
- * to V8's Error.captureStackTrace. See
- * https://code.google.com/p/v8/wiki/JavaScriptStackTraceApi.
- */
-RAW_DART_FUNCTION_REF(Function function) {}
-
-/**
  * Sets the current isolate to [isolate].
  */
 void JS_SET_CURRENT_ISOLATE(isolate) {}
 
 /**
  * Creates an isolate and returns it.
  */
 JS_CREATE_ISOLATE() {}
 
 /**
@@ skipping 125 matching lines @@
 }
 
 /**
  * JavaScript string concatenation. Inputs must be Strings.  Corresponds to the
  * HStringConcat SSA instruction and may be constant-folded.
  */
 String JS_STRING_CONCAT(String a, String b) {
   // This body is unused, only here for type analysis.
   return JS('String', '# + #', a, b);
 }