* gold/archive.h (Add_lib_group_symbols): Add readsyms_blocker_, adjust

	* gold/archive.h (Add_lib_group_symbols): Add readsyms_blocker_, adjust
	constructor, and set_blocker.
	* gold/archive.cc (Add_lib_group_symbols::is_runnable): Also check
	readsyms_blocker_.
	* gold/readsyms.cc (Read_symbols::do_lib_group): Also pass
	this->this_blocker_ to Add_lib_group_symbols::set_blocker.
	* testsuite/Makefile.am (start_lib_test): New test case.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/start_lib_test_main.c: New file.
	* testsuite/start_lib_test_1.c: New file.
	* testsuite/start_lib_test_2.c: New file.
	* testsuite/start_lib_test_3.c: New file.