[TIMOB-20422] iOS: Ti.UI.iOS.SystemButton is undefined.

Reproduce

According to the docs page (http://docs.appcelerator.com/platform/latest/#!/api/Titanium.UI.iPhone.SystemButton) Ti.UI.iPhone.SystemButton should be DEPRECATED, and we should use Ti.UI.iOS.SystemButton instead.But when doing test for this, Ti.UI.iOS.SystemButton is undefined, however, Ti.UI.iPhone.SystemButton works well.

Test Code

var win = Titanium.UI.createWindow({
    backgroundColor: 'white',
});

var done = Ti.UI.createButton({
	top: 20,
	title: 'Done', 
	systemButton: Ti.UI.iPhone.SystemButton.DONE;
        // systemButton: Ti.UI.iOS.SystemButton.DONE;
}); 

win.add(done);