target/loongarch: Implement xvsll xvsrl xvsra xvrotr

This patch includes:
- XVSLL[I].{B/H/W/D};
- XVSRL[I].{B/H/W/D};
- XVSRA[I].{B/H/W/D};
- XVROTR[I].{B/H/W/D}.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230914022645.1151356-36-gaosong@loongson.cn>
3 files changed