* archive.cc (Should_include): Move to archive.h.
	(should_include_member): Make it a member of Archive.
	(Lib_group): New.
	(Add_lib_group_symbols): New.
	* archive.h: Include options.h.
	(Archive_member): Moved from Archive.
	(Should_include): Moved from archive.cc.
	(Lib_group): New.
	(Add_lib_group_symbols): New.
	* dynobj.cc (do_should_include_member): New.
	* dynobj.h (do_should_include_member): New.
	* gold.cc (queue_initial_tasks): Update call to queue.
	* main.cc (main): Print lib group stats.
	* object.cc (do_should_include_member): New.
	* object.h: Include archive.h.
	(Object::should_include_member): New.
	(Object::do_should_include_member): New.
	(Sized_relobj::do_should_include_member): New.
	* options.cc (General_options::parse_start_lib): New.
	(General_options::parse_end_lib): New.
	(Input_arguments::add_file): Handle lib groups.
	(Input_arguments::start_group): Check we are not in a lib.
	(Input_arguments::start_lib): New.
	(Input_arguments::end_lib): New.
	* options.h (General_options): Add start_lib and end_lib.
	(Input_argument::lib_): New.
	(Input_argument::lib): New.
	(Input_argument::is_lib): New.
	(Input_file_lib): New.
	(Input_arguments::in_lib_): New.
	(Input_arguments::in_lib): New.
	(Input_arguments::start_lib): New.
	(Input_arguments::end_lib_): New.
	* plugin.cc (Pluginobj::get_symbol_resolution_info): Mark symbols
	in unused members as preempted.
	(Sized_pluginobj::do_should_include_member): New.
	* plugin.h (Sized_pluginobj::do_should_include_member): New.
	* readsyms.cc (Read_symbols::locks): If we are just reading a member,
	return the blocker.
	(Read_symbols::do_whole_lib_group): New.
	(Read_symbols::do_lib_group): New.
	(Read_symbols::do_read_symbols): Handle lib groups.
	(Read_symbols::get_name): Handle lib groups.
	* readsyms.h (Read_symbols): Add an archive member pointer.
	(Read_symbols::do_whole_lib_group): New.
	(Read_symbols::do_lib_group): New.
	(Read_symbols::member_): New.
	* script.cc (read_input_script): Update call to queue_soon.