Description:
------------
when a dynamic constant string is concatenated with another string anywhere in a class definition, php will segfault if opcache is enabled.

simply including the class is enough to trigger the segfault.

php does not segfault with opcache disabled or if using integers as the dynamic constant values.

Test script:
---------------
<?php
class Foo {
    const FOO = 'Foo';
    const FOOBAR = self::FOO.'Bar';
  
    function baz() {
    	$segfault = self::FOOBAR.'Baz';
    }
}

Expected result:
----------------
Expected result: No segfault

$ php --info | grep opcache.enable_cli
opcache.enable_cli => Off => Off
$ php foo.php
$


Actual result:
--------------
Actual result: PHP Segfaults

$ php --info | grep opcache.enable_cli
opcache.enable_cli => On => On
$ php foo.php
Segmentation fault