your patches enabling Arm64's SVE 2.1 extension

[Jan Beulich]

Srinath,

may I ask against what specification these were written? There are many
aspects I can't bring in line with what DDI0596 from December has, i.e.
even newer than the patch (dating back to October), to a degree that I
have to even question gas/NEWS stating (supposedly complete) support for
the feature:

1) dupq uses encodings different from the doc, in part resulting in
   supposedly reserved encodings (tsz=0).

2) extq uses syntax (operands) pretty different from what the doc says.

3) ld1q and st1q expect a plain first register operand, not one enclosed
   in figure braces.

4) ld2q, ld3q, ld4q, st2q, st3q, and st4q don't permit a wrapping
   sequence of vector registers, when the doc using "modulo" imo can't be
   read any way other than meaning to permit that.

5) ld2q's scalar plus scalar encoding has bits 13 and 14 set, which is
   inconsistent not only with the doc, but also with ld3q and ld4q.

6) ld3q/st3q and ld4q/st4q scalar plus immediate forms demand an immediate
   that's a multiple of 2, when the doc says 3 and 4 respectively.

7) orqv, pmov, tblq, tbxq, uzpq{1,2}, and zipq{1,2} are entirely missing.

Despite being newer it's of course possible that documentation is what
actually needs fixing. Can you please clarify which way it is?

Thanks, Jan