Description:
------------
When a callback that invokes a static class method is passed to register_shutdown_function(), the function incorrectly accepts it and after that zend engine segfaults when trying to invoke the callback.

Reproduce code:
---------------
<?php
class try_class
{
	static public function main ()
	{
		register_shutdown_function (array ("self", "on_shutdown"));
	}

	static public function on_shutdown ()
	{
		printf ("CHECKPOINT\n");
	}
}

try_class::main ();
?>


Expected result:
----------------
Some kind of error message

Actual result:
--------------
A segmentation fault.