Implemented RFC: Replace "Missing argument" warning with "Too few arguments" exception

Implemented RFC: Replace "Missing argument" warning with "Too few arguments" exception
Squashed commit of the following:

commit 8b45fa2acb8cd92542a39e1e4720fe1f4fabc26c
Author: Dmitry Stogov <dmitry@zend.com>
Date:   Thu Jun 16 01:52:50 2016 +0300

    Separate slow path of ZEND_RECV into a cold function.

commit 9e18895ee59c64c93a96b1ba3061355c4663e962
Author: Dmitry Stogov <dmitry@zend.com>
Date:   Wed Jun 15 23:26:28 2016 +0300

    Required argument can't be IS_UNDEF anymore.

commit 662db66e3943d4455c65e4f987bb54abf724ecb2
Author: Dmitry Stogov <dmitry@zend.com>
Date:   Tue May 31 17:14:50 2016 +0300

    Replace "Missing argument" warning by "Too few arguments" exception.