Re: [rx] add initial rtx_costs() function

[nick clifton]

Hi DJ,

Initial implementation of RTX_COSTS target function for rx-elf.  Minor
increase in coremark scores, and enables division by multiplication of
reciprocals, tested on trunk and 4.7.  Ok for trunk and/or 4.7 branch?

        * config/rx/rx.c (TARGET_RTX_COSTS): Define.
        (rx_rtx_costs): New.

OK for both.

Cheers
  Nick