shm: add wl_shm_buffer_{get,set}_user_data
This allows library users to attach an arbitrary data pointer to a wl_shm_buffer. They can't use the wl_resource's since it's used by wayland-shm itself.
Signed-off-by: Simon Ser contact@emersion.fr
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
This allows library users to attach an arbitrary data pointer to a wl_shm_buffer. They can't use the wl_resource's since it's used by wayland-shm itself.
Signed-off-by: Simon Ser contact@emersion.fr