So we can use it there as well...
For now I've retained the zend_smart_str_public.h header, though
it would probably be better to just move that one struct into
zend_types.h.
# This is useful w/ distributors who like to build all things shared or don't
# provide the readline extension. Or if a user pefers readline's behavior over
# libedit which might be used by the distributor.