INT 21 - DOS 2+ - "EXIT" - TERMINATE WITH RETURN CODE
	AH = 4Ch
	AL = return code
Return: never returns
Notes:	unless the process is its own parent
	  (see [offset 16h]">#01378 [offset 16h] at AH=26h), all open files are closed and
	  all memory belonging to the process is freed
	all network file locks should be removed before calling this function
SeeAlso: AH=00h,AH=26h,AH=4Bh,AH=4Dh,INT 15/AH=12h/BH=02h,INT 20,INT 22
SeeAlso: INT 60/DI=0601h