[RFC] Undefined Variable Error Promotion

Internals, Following on from my previous thread, I think we are now in a position where we can begin formal discussions on an RFC to promote undefined variables to Error exceptions in PHP 9.0. I present: https://wiki.php.net/rfc/undefined_variable_error_promotion I still intend to bring other error promotions forward, potentially in collaboration with other developers, but as this is the biggest change, and the most likely to attract a large number of comments, I thought it deserving of a standalone RFC. Mark Randall