[RFC IDEA] Deprecate legacy type alias functions

Hi internals, With PHP 8.5 deprecating the legacy cast syntax (boolean, double, integer, binary) in favor of bool, float, int, and string, I noticed that several legacy alias functions are still present in the language: • is_double, which is an alias of is_float • is_integer and is_long, both aliases of is_int • doubleval, which is an alias of floatval For reference, is_real was deprecated in PHP 7.4 and removed in 8.0. Given the recent move toward clearer and more consistent type naming, it seems consistent to consider deprecating these remaining alias functions as well, since they reflect the same legacy terminology that the cast changes aim to clean up. I found that this idea was mentioned before in a broader deprecation ideas thread targeting PHP 8, where variable handling function aliases such as is_double, is_integer and is_long were listed as candidates for potential cleanup. As far as I can tell, that discussion did not result in a dedicated RFC or vote on these specific aliases. https://externals.io/message/103779#103805 Before drafting a formal RFC, I would like to confirm whether there have been more recent discussions or prior decisions on this topic that I may have missed. If not, I would be happy to prepare a concrete proposal for further discussion. — Regards, Jordi Kroon