tnum_or
struct tnum tnum_or(struct tnum a, struct tnum b);
return tnum_or(tnum_clear_subreg(reg), tnum_subreg(subreg));
dst_reg->var_off = tnum_or(dst_reg->var_off, src_reg.var_off);
t = tnum_or(tnum_subreg(reg1->var_off), tnum_const(val));
reg1->var_off = tnum_or(reg1->var_off, tnum_const(val));
reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off);