tcg/loongarch64: Fix tcg_out_mov() Aborted

tcg/loongarch64: Fix tcg_out_mov() Aborted

On LoongArch host,  we got an Aborted from tcg_out_mov().

qemu-x86_64 configure with '--enable-debug'.

> (gdb) b /home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc:312
> Breakpoint 1 at 0x2576f0: file /home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc, line 312.
> (gdb) run hello
[...]
> Thread 1 "qemu-x86_64" hit Breakpoint 1, tcg_out_mov (s=0xaaaae91760 <tcg_init_ctx>, type=TCG_TYPE_V128, ret=TCG_REG_V2,
>     arg=TCG_REG_V0) at /home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc:312
> 312           g_assert_not_reached();
> (gdb) bt
> #0  tcg_out_mov (s=0xaaaae91760 <tcg_init_ctx>, type=TCG_TYPE_V128, ret=TCG_REG_V2, arg=TCG_REG_V0)
>     at /home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc:312
> #1  0x000000aaaad0fee0 in tcg_reg_alloc_mov (s=0xaaaae91760 <tcg_init_ctx>, op=0xaaaaf67c20) at ../tcg/tcg.c:4632
> #2  0x000000aaaad142f4 in tcg_gen_code (s=0xaaaae91760 <tcg_init_ctx>, tb=0xffe8030340 <code_gen_buffer+197328>,
>     pc_start=4346094) at ../tcg/tcg.c:6135
[...]
> (gdb) c
> Continuing.
> **
> ERROR:/home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc:312:tcg_out_mov: code should not be reached
> Bail out! ERROR:/home1/gaosong/code/qemu/tcg/loongarch64/tcg-target.c.inc:312:tcg_out_mov: code should not be reached
>
> Thread 1 "qemu-x86_64" received signal SIGABRT, Aborted.
> 0x000000fff7b1c390 in raise () from /lib64/libc.so.6
> (gdb) q

Fixes: 16288ded94 ("tcg/loongarch64: Lower basic tcg vec ops to LSX")
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20231120065916.374045-1-gaosong@loongson.cn>