Needs Feedback - Yield without value in reference generator function does not create notice

Hello everyone, In this issue #16761 <https://github.com/php/php-src/issues/16761> it was verified that in the above code it should throw a notice for both yields: ``` <?phperror_reporting(E_ALL);function &y() { yield null; // warning yield; // no warning, agreed to be a bug }foreach (y() as &$y); ``` I have created this PR <https://github.com/php/php-src/pull/16882> which adds the "missing" notice but we aren't sure on how to continue on this. There are 2 main questions: 1. Should we continue with adding the missing notice and merge it also in master? 2. Should we deprecate / remove the usage of yield without value in reference generator functions? - Aggelos Bellos