PR 10980

	PR 10980
	* options.h (class General_options): Add --undefined-version.
	* script.cc (struct Version_expression): Add was_matched_by_symbol
	field.
	(Version_script_info::matched_symbol): New function.
	(Version_script_info::get_symbol_version_helper): Call
	matched_symbol.
	(Version_script_info::check_unmatched_names): New function.
	* script.h (class Version_script_info): Update declarations.
	* gold.cc (queue_middle_tasks): Handle --no-undefined-version.