Fixed incorrect check. SEND_REF may be executed before DO_FCALL when EX(function_state).function is not yet set to the calling function.
Merge branch 'PHP-5.3' into PHP-5.4

* PHP-5.3:
  Fixed incorrect check. SEND_REF may be executed before DO_FCALL when EX(function_state).function is not yet set to the calling function.

Conflicts:
	Zend/zend_vm_def.h
	Zend/zend_vm_execute.h