INT 15 - TopView - "SETBIT" - SCHEDULE ONE OR MORE 2ND-LEVEL INTERRUPTS

	AX = 1015h
	BX = bit mask for interrupts to post
Return: indicated routines will be called: (DV 2.0x) at next task switch
					   (DV 2.2x) immediately on return from
						     hardware interrupt
Notes:	this is one of the few TopView calls which are allowed from a hardware
	  interrupt handler
	the handler will be called with ES containing the segment of the handle
	  of the next task to be executed; on return, ES must be the segment of
	  a task handle
SeeAlso: AX=1013h,AX=1014h