> We can either use NDS32_FD0_REGNUM or gdbarch_tdep.fd0_regnum, IMO.  If
> the register number of fd0 is fixed, we can use NDS32_FD0_REGNUM,
> otherwise, we need to use gdbarch_tdep.fd0_regnum.  If so, we can remove
> one of them.
>

Hi Yao,

Thanks for the review.

Currently, the register number of fd0, if present, is always fixed, so
all usage of gdbarch_tdep.fd0_regnum is replaced with
NDS32_FD0_REGNUM.
In addition, after reviewing the flow to initialize gdbarch_tdep, the
allocation and initialization of gdbarch_tdep is put just before the
allocation of gdbarch.

The modified patch is attached, please help to review again.
Thanks a lot.