arc: Update vector instructions

[Claudiu Zissulescu Ianculescu]

Thank you, I'll look into it asap.

Best,
Claudiu

On Wed, Jul 8, 2020 at 9:48 AM Alan Modra <amodra@gmail.com> wrote:
>
> oss-fuzz found a problem with this patch, reporting an access past the
> end of regnames[] at arc-dis.c:1276
>
> To see it, "objdump -d -Mcpu=em" on the following.
>  .text
>  .byte 0x9e,0x2f,0x20,0x75
>
> --
> Alan Modra
> Australia Development Lab, IBM