Description:
------------
bcscale uses long typed variable to store scale passed further to bclib calls. Unfortunately bclib uses int type for scale parameter, thus large long numbers (which uses 8 bytes on 64 bits platforms) could be casted to negative number and cause memory corruption as a result of pointer arithmetic with scale param.

Test script:
---------------
<?php
$var48 = bcscale(634314234334311);
$var67 = bcsqrt(false);
$var414 = bcadd(false,null,10);
die('ALIVE');
?>

Expected result:
----------------
ALIVE

Actual result:
--------------
$ php
<?php
$var48 = bcscale(634314234334311);
$var67 = bcsqrt(false);
$var414 = bcadd(false,null,10);
die('ALIVE');
?>^D
Segmentation fault: 11 (core dumped)