[PING^3][PATCH] RISC-V: Add support for XXTVarith and XXTVcoder extensions

[Kito Cheng]

Committed after passing testsuite :)

Kito Cheng <kito.cheng@gmail.com> 於 2026年9月2日週三 上午11:06寫道：
>
> Give a quick review, it's just add new instruction without adding new
> modifier so LGTM, but I am not official RISC-V binutils
> maintainer...:P
>
> Bohan Lei <garthlei@linux.alibaba.com> 於 2026年9月2日週三 上午10:23寫道：
> >
> > Sorry for the duplication due to email formatting issues.
> > Ping.  Could anyone help review the vendor-extension patch?
> > Link: https://patchwork.sourceware.org/project/binutils/patch/20260708024729.54397-1-garthlei@linux.alibaba.com/