Freeing cc tables doesn't need access to ID

We don't need to resolve symbols when freeing cc tables, so this commit
just changes the id table iterator to look at values rather than keys
and values.

gc.c

@@ -2522,7 +2522,7 @@ cc_table_mark(rb_objspace_t *objspace, VALUE klass)
 }
 
 static enum rb_id_table_iterator_result
-cc_table_free_i(ID id, VALUE ccs_ptr, void *data_ptr)
+cc_table_free_i(VALUE ccs_ptr, void *data_ptr)
 {
     struct cc_tbl_i_data *data = data_ptr;
     struct rb_class_cc_entries *ccs = (struct rb_class_cc_entries *)ccs_ptr;
@@ -2542,7 +2542,7 @@ cc_table_free(rb_objspace_t *objspace, VALUE klass, bool alive)
             .klass = klass,
             .alive = alive,
         };
-        rb_id_table_foreach(cc_tbl, cc_table_free_i, &data);
+        rb_id_table_foreach_values(cc_tbl, cc_table_free_i, &data);
         rb_id_table_free(cc_tbl);
     }
 }