INT 15 - TopViewTopView, DESQview, TaskView, OmniView, other compatibles - "FREEBIT" - UNDEFINE A 2ND-LEVEL INTERRUPT HANDLER
	AX = 1014h
	BX = bit mask from INT 15/AX=1013h
Return: nothing
SeeAlso: AX=1013h,AX=1015h