POPA/POPAD - Pop All Registers onto Stack (80188+ only)

	Usage:	POPA
		POPAD  (386+ only)
	Modifies flags: None

	Pops the top 8 words off the stack into the 8 general purpose 16/32
	bit registers.	 Registers are popped in the following order: (E)DI,
	(E)SI, (E)BP, (E)SP, (E)DX, (E)CX and (E)AX.  The (E)SP value popped
	from the stack is actually discarded.

				 Clocks			Size
	Operands	 808x  286   386   486		Bytes

	none		  -	19    24    9		  1

	- see Instruction Timing