CDQ - Convert Double to Quad (386+ only)

	Usage:	CDQ
	Modifies flags: None


	Converts signed DWORD in EAX to a signed quad word in EDX:EAX by
	extending the high order bit of EAX throughout EDX


				 Clocks			Size
	Operands	 808x  286   386   486		Bytes

	none		  -	-     2	    3		  1


	- see Instruction Timing