INT 15 - MultiDOS Plus - TEST RESOURCE SEMAPHORE BY NAME
        AH = 1Dh
        DS:SI -> 8-byte name
Return; AH = status
            00h semaphore not in use
            01h semaphore owned by another task
            02h invalid semaphore number
            03h caller owns semaphore
            04h out of string space
Notes:  (see AH=10h"MultiDOS")
        equivalent to AH=1Ah followed by AH=10h
SeeAlso: AH=1Ah"MultiDOS",AH=1Bh"MultiDOS",AH=1Ch"MultiDOS"