MOVSX - Move with Sign Extend (386+ only)

	Usage:	MOVSX	dest,src
	Modifies flags: None


	Copies the value of the source operand to the destination register
	with the sign extended.


				 Clocks			Size
	Operands	 808x  286   386   486		Bytes

	reg,reg 	  -	-     3	    3		  3
	reg,mem 	  -	-     6	    3		 3-7


	- see Instruction Timing