PR 995
* ar.c (BUFSIZE): Moved to ...
* bucomm.h (BUFSIZE): Here.
* bucomm.c: Include <assert.h>.
(bfd_get_archive_filename): New.
* bucomm.h (bfd_get_archive_filename): New.
* objcopy.c (copy_unknown_object): New.
(copy_object): Use bfd_get_archive_filename when reporting input
error. Don't call fatal on unknown arch.
(copy_archive): Call copy_unknown_object on unknown format or
arch.