[PATCH v2] Support Intel FRED LKGS

[Jiang, Haochen]

> Well, there are two ways of approaching this, but imo in either case via
> a prereq change to the other insns that use this operand descriptor in a
> questionable manner. We could split decode at the ModR/M.mod level, but
> perhaps better is to follow MOV to/from sreg, SLDT, and STR in using a D
> suffix and an Sv operand.

I suppose the latter is better since Sv will go back to OP_E then split decode
ad ModR/M.mod level.

I will go through that to make the change.

Thx,
Haochen

> 
> If, however, you're not happy about making the prereq change first, I'd
> be kind of okay with the change being committed as is, and I'd then try
> to remember to follow up accordingly. One minor adjustment request,
> though: In the opcode table comments, can you please use singular for
> LKGS (while plural is fine for FRED)?
> 
> Jan