php/php-src — pull request #551 by realityking (2013-12-25 16:07:20+00:00)
Title: Add ZEND_ARG_CALLABLE_INFO to allow internal function to type hint against callable.

For some reason this macro is missing. Confirmed in local testing that it works but can't provide any unit tests since it's not used in PHP core.

Pull request is against 5.4 since that's the version callable was introduced.