bl_desc           331 net/zlib.c         struct tree_desc_s bl_desc;              /* desc. for bit length tree */
bl_desc          1763 net/zlib.c         s->bl_desc.dyn_tree = s->bl_tree;
bl_desc          1764 net/zlib.c         s->bl_desc.stat_desc = &static_bl_desc;
bl_desc          2182 net/zlib.c         build_tree(s, (tree_desc *)(&(s->bl_desc)));