* config/rs6000/tm-rs6000.h (FP0_REGNUM): Document that this

* config/rs6000/tm-rs6000.h (FP0_REGNUM): Document that this
should no longer be used in code specific to the RS6000 and its
derivatives.
* ppc-tdep.h (struct gdbarch_tdep): Add 'ppc_fp0_regnum' member.
* rs6000-tdep.c (rs6000_gdbarch_init): Initialize
tdep->ppc_fp0_regnum.
(ppc_supply_fpregset, ppc_collect_fpregset)
(rs6000_push_dummy_call, rs6000_extract_return_value)
(rs6000_dwarf2_stab_reg_to_regnum, rs6000_store_return_value)
(rs6000_frame_cache): Use tdep->ppc_fp0_regnum instead of
FP0_REGNUM.
* aix-thread.c (supply_fprs, fetch_regs_kernel_thread)
(fill_gprs64, fill_gprs32, fill_fprs, store_regs_kernel_thread):
Same.
* ppc-bdm.c (bdm_ppc_fetch_registers, bdm_ppc_fetch_registers,
bdm_ppc_store_registers): Same.
* ppc-linux-nat.c (ppc_register_u_addr, fetch_register)
(store_register, fill_fpregset): Same.
* ppc-linux-tdep.c (ppc_linux_sigtramp_cache)
(ppc_linux_supply_fpregset): Same.
* ppcnbsd-nat.c (getfpregs_supplies): Same.
* ppcnbsd-tdep.c (ppcnbsd_supply_fpreg, ppcnbsd_fill_fpreg):
Same.
* ppc-sysv-tdep.c (ppc_sysv_abi_push_dummy_call,
do_ppc_sysv_return_value, ppc64_sysv_abi_push_dummy_call,
ppc64_sysv_abi_return_value): Same.
* rs6000-nat.c (regmap, fetch_inferior_registers)
(store_inferior_registers, fetch_core_registers): Same.