Description:
------------
Exception backtrace produces wrong integer values when passed by reference - a regression VS PHP 5.x, as can be seen in the test script.

Test script:
---------------
<pre><?php
function recurse_bug($count) {
	if ($count) {
		return recurse_bug(--$count); // if we use instead $count - 1, then BT will be prodcued OK on PHP 7 too
	}
	$e = new Exception();
	print $e->getTraceAsString();
}
recurse_bug(2);
/*  On PHP 5.x we will get the correct BT:
#0 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#1 /var/www/html/frontend/scrap.php(4): recurse_bug(1)
#2 /var/www/html/frontend/scrap.php(9): recurse_bug(2)
#3 {main}

On PHP 7.x we will get the following wrong BT:
#0 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#1 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#2 /var/www/html/frontend/scrap.php(9): recurse_bug(1)
#3 {main} */

Expected result:
----------------
#0 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#1 /var/www/html/frontend/scrap.php(4): recurse_bug(1)
#2 /var/www/html/frontend/scrap.php(9): recurse_bug(2)
#3 {main}

Actual result:
--------------
#0 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#1 /var/www/html/frontend/scrap.php(4): recurse_bug(0)
#2 /var/www/html/frontend/scrap.php(9): recurse_bug(1)
#3 {main} */