[modules] Don't throw when detecting cycle while processing star exports.

test/mjsunit/modules-fail-star-exports-conflict.js

 // 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.
 //
 // MODULE
 
-import foo from "modules-skip-1.js";
-assertEquals(42, foo);
+export * from "modules-skip-star-exports-conflict.js";
+export * from "modules-skip-6.js";
 
-import {default as gaga} from "modules-skip-1.js";
-assertEquals(42, gaga);
+import {a} from "modules-fail-star-exports-conflict.js";