feature options define combo like auto/yes/no in a standand way. In other words, upstream projects of ports that use _MESON_YES are supposed to migrate to _MESON_ENABLED. https://mesonbuild.com/Build-options.html#features Reviewed by: tobik (implicit) Approved by: portmgr (mat) Differential Revision: https://reviews.freebsd.org/D19127