INT 2F U - DOS 3.3+ internal - IOCTL                                            
	AX = 122Bh
	BP = 44xxh
	SS = DOS DS (must be using a DOS internal stack)
	additional registers as appropriate for INT 21/AX=44xxh
Return: as for INT 21/AH=44h
Notes:	equivalent to INT 21/AH=44h, but may only be called when already inside
	  a DOS function call
	sets user stack frame pointer to dummy buffer, moves BP to AX, performs
	  IOCTL, and restores frame pointer
	used by NLSFUNC in accessing COUNTRY.SYS when invoked by the DOS kernel
SeeAlso: INT 21/AH=44h