Zend: mark zend_free_internal_arg_info() static

[Girgias]

Previously it was used by the disable_classes INI, as this no longer exists there is no need to expose it.

[TimWolla]

Isn't even marked ZEND_API, so makes sense and probably doesn't even need an UPGRADING.INTERNALS note.

[Girgias]

@arnaud-lb seems you exposed this as a ZEND_API for PDO, can you give some more insights into why this is needed?

[arnaud-lb]

@Girgias yes it's ZEND_API since 626f3c3. It's needed to free the arg_info of temporary temporary internal methods, like the ones added by PDO:

php-src/ext/pdo/pdo_dbh.c

Line 1324 in 626f3c3

zend_free_internal_arg_info(&func->internal_function, false);

The reason it wasn't needed before 626f3c3, is that arg_info was in static storage.

This may be useful outside of PDO, if some other extensions declare temporary internal methods. If we don't want to support this, we could un-export zend_free_internal_arg_info() when removing the deprecated PDO methods later.

An alternative to exposing zend_free_internal_arg_info() would be to provide a variant of zend_function_dtor() suitable for cls_method_dtor() / cls_method_pdtor().