BT - Bit Test (386+ only)

	Usage:	BT	dest,src
	Modifies flags: CF


	The destination bit indexed by the source value is copied into the
	Carry Flag.


				 Clocks			Size
	Operands	 808x  286   386   486		Bytes

	reg16,immed8	  -	-     3	    3		 4-8
	mem16,immed8	  -	-     6	    6		 4-8
	reg16,reg16	  -	-     3	    3		 3-7
	mem16,reg16	  -	-     12    12		 3-7


	- see Instruction Timing