[DYNAREC_RV64] Fixed A0 MOV AL,Ob

[ksco]

No description provided.

[ksco]

I fixed rv64_move32 in 9861c4f above! On a very rare condition, the original implementation could be wrong: like MOV64x(x1, 0x7fffffff0000).

Original:

        lui     a0, 524288 // 0x80000
        addi    a0, a0, -1
        slli    a0, a0, 16
        ret

Fixed:

        lui     a0, 524288 // 0x80000
        addiw   a0, a0, -1
        slli    a0, a0, 16
        ret