Fix typechecking of mutually recursive functions.

code/compiler/12/definition.cpp

@@ -139,7 +139,7 @@ void definition_group::typecheck(type_mgr& mgr, type_env_ptr& env) {
             def_defn->typecheck(mgr);
         }
         for(auto& def_defnn_name : group->members) {
-            this->env->generalize(def_defnn_name, mgr);
+            this->env->generalize(def_defnn_name, *group, mgr);
         }
     }
 }