Enable Intel AVX512_FP16 instructions and test

[Cui, Lili]

> >>>> I'm not sure a new insn attribute is warranted here (iirc you got
> >>>> away without for the AMX special restrictions), but I also don't
> >>>> really want to request that you redo this. What I would like to see
> >>>> improved though is the
> >>>> name: It would better express that it's the destination that needs
> >>>> to be distinct (unlike for the AMX insns, where all registers need
> >>>> to be
> >> distinct).
> >>>> Also the error message wording "destination and source registers
> >>>> must be distinct" is ambiguous (one may read it to mean the same as
> >>>> what the AMX requirement is). I'd suggest "destination must be
> >>>> distinct from source registers".
> >>>>
> >>> Done.
> >>
> >> Hmm, I see you've changed the message (which, seeing it again, is
> >> still ambiguous I'm afraid), but you've kept the field name.
> >>
> > How about ReqDistinctDest ?
> 
> Quite a bit better, yes. Perhaps even drop the "Req" part of it?
> 
Dropped it.

> >> As to the message (I'm sorry for adjusting my prior suggestion), how
> >> about "destination must be distinct from source registers"?
> >>
> > I am confused here, do I need to make some changes ?
> 
> Well - use the new suggested text?
> 
Done.

Thanks,
Lili.