[Mirroring] The layoutDirection style/property doesnt code hint static enums

Found in 4.1.0.14607

Steps to reproduce:
1. Copy and paste following .MXML file:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
layoutDirection="">

<s:Button layoutDirection="" />
<mx:Button layoutDirection="" />

</s:Application>

2. Try and get code hints for layoutDirection static consts ("ltr" and "rtl").

Actual Results:
No hints.

Expected Results:
Hints me.

Workaround (if any):
Consult documentation for static consts.

For things like UIComponent.blendMode, we have the following metadata:

[Inspectable(category="General", enumeration="add,alpha,darken,difference,erase,hardlight,invert,layer,lighten,multiply,normal,subtract,screen,overlay,colordodge,colorburn,exclusion,softlight,hue,saturation,color,luminosity", defaultValue="normal")]

/**

• @private
  */
  override public function get blendMode():String { return _blendMode; }