why line in ebuild cannot look like this USE_PHP="php5-3 php5-4 php5-5 php5-6" I know its deprecated , but milions still use it and it will not change for next 2 years at least or why u remove old ebuilds which have not security problems and still works for old builds. like 3.0.1
How can you say that an unmaintained version does not have any security issues? Just upgrade to PHP 5.5 or later. You have to do it eventually, and the job is not getting any easier the more you postpone.