Description:
------------
If I assign an instance of the Closure object as a property of an 
object, I would expect to be able to execute that property as a 
function.

E.g.

$o = new stdClass;

$o->test = function(){
	echo "Executing function";	
};

I would expect this to work:

$o->test();

However, it does not. This does:

call_user_func($o->test);

The $o->test() syntax is more concise and in keeping with other 
languages with such features.

Reproduce code:
---------------
$o = new stdClass;

$o->test = function(){
	echo "Executing function";	
};

$o->test();

Expected result:
----------------
Executing function

Actual result:
--------------
PHP Fatal error:  Call to undefined method stdClass::test()