Where is P_THREADED?

For a couple of days now, I've been trying to advance from 5.1-RELEASE
to -CURRENT.  I havn't been able to compile the kernel, however, as
even 'make buildkernel' (after having done a 'make buildworld') fails
looking for a P_THREADED symbol in kern_synch.c.

Since it's not very likely that I can do without _that_ file in the
kernel, I waited a few days and tried the whole thing again with a new
cvsup.  Still no go.  So I tried 'make include' ... still no go.  So I
tried:

[4:10:310]root_at_canoe:/usr/src> find . -type f | xargs grep P_THREADED
./sys/kern/kern_synch.c:        if (p->p_flag & P_THREADED || p->p_numthreads > 1) {
./sys/kern/kern_synch.c:        if (td->td_proc->p_flag & P_THREADED)

... so if P_THREADED doesn't exist in the /usr/src tree, where would I
be finding it?

Dave.

-- 
============================================================================
|David Gilbert, Velocet Communications.       | Two things can only be     |
|Mail:       dgilbert_at_velocet.net             |  equal if and only if they |
|http://daveg.ca                              |   are precisely opposite.  |
=========================================================GLO================