Last argument (FILE *) for apache_php3_module_main does not exist in function, but it is in declaration:

main.c:PHPAPI int apache_php3_module_main(request_rec * r, int fd, int display_source_mode, int preprocessed)
mod_php3.c:extern int apache_php3_module_main(request_rec *, int, int, int, FILE *);
mod_php3.c:     apache_php3_module_main(r, fd, display_source_mode, preprocessed, NULL);