target/loongarch: Implement vseq vsle vslt

This patch includes:
- VSEQ[I].{B/H/W/D};
- VSLE[I].{B/H/W/D}[U];
- VSLT[I].{B/H/W/D/}[U].

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20230504122810.4094787-36-gaosong@loongson.cn>
5 files changed