target/loongarch: Implement vbitclr vbitset vbitrev

This patch includes:
- VBITCLR[I].{B/H/W/D};
- VBITSET[I].{B/H/W/D};
- VBITREV[I].{B/H/W/D}.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230504122810.4094787-32-gaosong@loongson.cn>
5 files changed