Description:
------------
This bug/feature request has some relation with bug: #25640. 

I've loaded XML into a simpleXML object. SimpleXML currently loads empty tags (e.g. <tag />) as empty SimpleXML objects.

With the SimpleXML object I wanted to use the following code to find out whether a tag has child tags or not:

if (is_object($SimpleXMLObjectNode)) {
   // $node has child tags

Unfortunately this doesn't work very well since this code will think that empty tags have child tags too. (Since empty tags are loaded as objects)

Therefore I thought it would be a nice feature to be able to find out whether an object is empty or not. Something like:

if (empty($object)) {
   // Object is empty
}

Reproduce code:
---------------
<?php
$xml = '<wrapper><foo></foo><bar>s2</bar><bar>s3</bar></wrapper>';
$t = simplexml_load_string($xml);
print_r($t);
if (empty($t->foo)) {
	echo 'Tag is empty';
} else {
	echo 'Tag has contents';
}
?>

Expected result:
----------------
Tag is empty

Actual result:
--------------
Tag has contents