Description:
------------
See the Code

Reproduce code:
---------------
<?php
$string = str_repeat("foobarbazbang", 2000);

var_dump(
    preg_match('/^([\x00-\x7f]|'.
        '[\xc2-\xdf][\x80-\xbf]|' . 
        '\xe0[\xa0-\xbf][\x80-\xbf]|' . 
        '[\xe1-\xec][\x80-\xbf]{2}|' . 
        '\xed[\x80-\x9f][\x80-\xbf]|' . 
        '[\xee-\xef][\x80-\xbf]{2}|' . 
        'f0[\x90-\xbf][\x80-\xbf]{2}|' . 
        '[\xf1-\xf3][\x80-\xbf]{3}|' . 
        '\xf4[\x80-\x8f][\x80-\xbf]{2})*$/',
    $string)
);

Actual result:
--------------
Backtrace:
[New Thread -1216595648 (LWP 25629)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1216595648 (LWP 25629)]
0x080b7876 in match (
    eptr=0x87af93c "oobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobar"...,     ecode=0x87e14c5 "^",     mstart=0x87aeeec "foobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfoobarbazbangfooba"...,     offset_top=4, md=0xbffbf8ec, ims=0, eptrb=0x0, flags=0, rdepth=5281)    at /usr/src/php5/ext/pcre/pcrelib/pcre_exec.c:575575     utf8 = md->utf8;       /* Local copy of the flag */