* archive.cc (Archive::include_member): Update calls to add_symbols.
	* dynobj.cc (Sized_dynobj<size, big_endian>::make_version_map): Add
	the Layout argument.
	* dynobj.h (do_add_symbols): Add the Layout argument.
	* object.cc (Sized_relobj<size, big_endian>::do_add_symbols): Add the
	Layout argument.
	* object.h (Object::add_symbols): Add the Layout argument.
	(Object::do_add_symbols): Add the Layout argument.
	(Sized_relobj::do_add_symbols): Add the Layout argument.
	* plugin.cc (Sized_pluginobj<size, big_endian>::do_add_symbols):
	Unify the two versions.
	(Add_plugin_symbols): Remove.
	* plugin.h (Pluginobj::add_symbols, Pluginobj::do_add_symbols): Remove.
	(Sized_pluginobj::do_add_symbols): Unify the two versions.
	(Add_plugin_symbols): Remove.
	* readsyms.cc (Read_symbols::do_read_symbols): Update call to
	Add_symbols. Use Add_symbols instead of Add_plugin_symbols.
	(Add_symbols::run): Make it work with Pulginobj.