Description:
------------
---
From manual page: http://www.php.net/function.preg-match#refsect1-function.preg-
match-changelog
---

The function signature for preg_match indicates $matches (the third argument) is 
optional. However, it was only made optional in PHP 5.4.0:

http://php.net/ChangeLog-5.php#5.4.0
""""
Improved preg extension
Changed third parameter of preg_match_all() to optional. #53238.
""""

The changelog for this function should reflect this, so that readers still using 
versions earlier than PHP 5.4 will understand why they get errors if they 
attempt to leave off the third argument.

Expected result:
----------------
I would expect the changelog for the preg_match function documentation to show 
that the third argument was made optional in PHP 5.4.0.