bfd/

bfd/
	* elf-bfd.h (_bfd_elf_slurp_version_tables): Update prototype.
	* elf.c (_bfd_elf_print_private_bfd_data): Pass extra argument.
	(_bfd_elf_slurp_version_tables): Add extra argument.  Create extra
	default version definition for unversioned symbols.
	* elfcode.h (elf_slurp_symbol_table): Pass extra argument.
	* elflink.c (elf_link_add_object_symbols): Pass extra argument to
	_bfd_elf_slurp_version_tables.  Set default version for unversioned
	imported symbols.
include/
	* bfdlink.h (bfd_link_info): Add default_imported_symver.
ld/
	* ld.texinfo: Document --default-imported-symver.
	* ldmain.c (main): Set link_info.default_imported_symver.
	* lexsup.c (option_values): Add OPTION_DEFAULT_IMPORTED_SYMVER.
	(ld_options): Add --default-imported-symver.
	(parse_args): Handle OPTION_DEFAULT_IMPORTED_SYMVER.