
Int21.714B - Long filename - Load and/or execute program
INP:	ax = 714Bh
	cl = mode
	ds:dx-> ASCIZ (long) filename
	es:bx-> parameter block
OUT:	CF unchanged, ax = 7100h if Int21.71 not supported
	CY on error,
	 ax = 0001h if function not supported
	NC if successful

This function is an extension supported by RxDOS only.
Error codes, modes and parameter blocks for each mode as for Int21.4B.