use_struct_convention to ppc_sysv_abi_broken_use_struct_convention.
* ppcnbsd-tdep.c: New file. * ppcnbsd-tdep.h: New file. * config/powerpc/nbsd.mh (NATDEPFILES): Remove corelow.o, solib.o, and solib-svr4.o. * config/powerpc/nbsd.mt (TDEPFILES): Add ppcnbsd-tdep.o, nbsd-tdep.o, and corelow.o.