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.
