Make type_env a class.

code/compiler/13/compiler.cpp

@@ -69,7 +69,7 @@ void compiler::translate() {
     }
     for(auto& defn : global_defs.defs_defn) {
         auto& function = defn.second->into_global(global_scp);
-        function.body->env->parent->set_mangled_name(defn.first, function.name);
+        function.body->env->get_parent()->set_mangled_name(defn.first, function.name);
     }
 }