Description:
------------
if you use -- on a variable inside a loop in global scope, it doesn't initialize the variable.  ++ does.


Reproduce code:
---------------
<?php
while ($aglobal < 10) {
	$aglobal++;
	$j--;
	$another = $j;
}

print "aglobal $aglobal, j $j, another $another\n";
?>


Expected result:
----------------
aglobal 10, j -10, another -10


Actual result:
--------------
aglobal 10, j , another