[modules] Improve error messages.

test/mjsunit/modules-skip-cyclic-3.js

Index: test/mjsunit/modules-skip-cyclic-3.js
diff --git a/test/mjsunit/modules-skip-cyclic-3.js b/test/mjsunit/modules-skip-cyclic-3.js
deleted file mode 100644
index ced96270b1e3e951180c3d6eddeb101e3092054b..0000000000000000000000000000000000000000
--- a/test/mjsunit/modules-skip-cyclic-3.js
+++ /dev/null
@@ -1,6 +0,0 @@
-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-export {y as a} from "modules-fail-cyclic-3.js";
-export {x as b} from "modules-fail-cyclic-3.js";