This reverts commit b690cb67be9b487eb10156c03e2c00869e88cc9d, reversing
changes made to 50dd431dffe5cf86e9064a652d6b01dbbe542cf0. This is
necessary because the reverted changeset reduced coverage by an unknown
extent.
Attempting to freeze the module namespace exotic object should not affect the `writable`-ity of the properties as that exercises the same `DefineOwnProperty` operation according to [`SetIntegrityLevel`](https://tc39.es/ecma262/#sec-setintegritylevel).
@erights discovered a [bug in v8](https://bugs.chromium.org/p/v8/issues/detail?id=12240) where, while the `Object.freeze` operation throws, it actually makes exported properties non-writable one by one.
At the request of @syg, I'm contributing a test against this behavior. The bug in v8 actually leads to a breakage of the objects invariants, however I'm not testing for that here as the root cause is the illegal freezing of the export.