_lwp_detach() causes a light-weight process to become detached, having the same effect as if the LWP was created with the
LWP_DETACHED flag.
The resources associated with a detached LWP will be automatically reclaimed by the system when the LWP exits. Conversely, an attached LWP's resources will not be reclaimed until its status is reported to another LWP via
_lwp_wait(2).