mark_tbl         1283 gc.c               mark_tbl(&rb_objspace, tbl, 0);
mark_tbl         1543 gc.c           	mark_tbl(objspace, RCLASS_M_TBL(obj), lev);
mark_tbl         1544 gc.c           	mark_tbl(objspace, RCLASS_IV_TBL(obj), lev);
mark_tbl         2025 gc.c           	mark_tbl(objspace, finalizer_table, 0);
mark_tbl         2041 gc.c               mark_tbl(objspace, rb_class_tbl, 0);