Fix slight issues with autocompletion and member lists in GDScript

Fixes #27152
Fixes #28591

(cherry picked from commit f9d95309024c7b7dac5c12b891cb90982f566565)

modules/gdscript/gdscript.cpp

@@ -226,7 +226,7 @@ void GDScript::get_script_method_list(List<MethodInfo> *p_list) const {
 
 	const GDScript *current = this;
 	while (current) {
-		for (const Map<StringName, GDScriptFunction *>::Element *E = member_functions.front(); E; E = E->next()) {
+		for (const Map<StringName, GDScriptFunction *>::Element *E = current->member_functions.front(); E; E = E->next()) {
 			GDScriptFunction *func = E->get();
 			MethodInfo mi;
 			mi.name = E->key();

modules/gdscript/gdscript_editor.cpp

@@ -1947,7 +1947,7 @@ static void _find_identifiers_in_base(const GDScriptCompletionContext &p_context
 					} else {
 						base_type.has_type = script->get_instance_base_type() != StringName();
 						base_type.kind = GDScriptParser::DataType::NATIVE;
-						base_type.script_type = script->get_instance_base_type();
+						base_type.native_type = script->get_instance_base_type();
 					}
 				} else {
 					return;