According to the specification, [X]VLDI should trigger an invalid instruction
exception only when Bit[12] is 1 and Bit[11:8] > 12. This patch fixes an issue
where an exception was incorrectly raised even when Bit[12] was 0.
Test case:
```
.global main
main:
vldi $vr0, 3328
ret
```
Reported-by: Zhou Qiankang <wszqkzqk@qq.com>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Reviewed-by: Song Gao <gaosong@loongson.cn>
Message-ID: <20250804132212.4816-1-wangrui@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
e66644c48e