target/loongarch: Add preldx instruction
Resolve the issue of starting the Loongnix 20.5[1] system failure.
Logs:
Loading Linux 4.19.0-19-loongson-3 ...
Loading initial ramdisk ...
PROGRESS CODE: V02010004 I0
PROGRESS CODE: V03101019 I0
Error: unknown opcode.
90000000003a3e6c: 0x382c6d82
[1] http://pkg.loongnix.cn/loongnix/isos/Loongnix-20.5/Loongnix-20.5.cartoon.gui.loongarch64.en.qcow2
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <
20230905123910.
3052023-1-gaosong@loongson.cn>