* options.h (Command_line::Pre_options): New class.

	* options.h (Command_line::Pre_options): New class.
	(Command_line::pre_options): New member.
	* options.cc (gold::options::ready_to_register): New variable.
	(One_option::register_option): Do nothing if not registering options.
	Assert if same short option registered twice.
	(General_options::General_options): Turn off option registration when
	done constructing.
	(Command_line::Pre_options::Pre_options): New constructor.