(fetch_regs_user_thread, fetch_regs_kernel_thread)
(store_regs_user_thread, store_regs_kernel_thread): Use
ppc_num_gprs and ppc_num_fprs instead of '32' and '31'.
* ppc-linux-nat.c (fill_gregset): Same.
* ppc-linux-tdep.c (ppc_linux_supply_gregset)
(ppc_linux_sigtramp_cache): Same.
* ppcnbsd-tdep.c (ppcnbsd_supply_reg, ppcnbsd_fill_reg)
(ppcnbsd_sigtramp_cache_init): Same.
* rs6000-nat.c (fetch_core_registers): Same.
* rs6000-tdep.c (ppc_supply_gregset, ppc_collect_gregset)
(rs6000_frame_cache): Same.