Adding case for super access of a module namespace TDZ binding

[caiolima]

This PR is adding a case where we have an access to a TDZ biding of a namespace module using super.prop. The case here is that we should throw a ReferenceError instead of a TypeError, because OrdinarySet calls Receiver.[[GetOwnProperty]] before it tries to write into the object. It's important to notice that Receiver is a namespace object, because super() will change this biding before super.foo gets executed, and OrdinarySet gets executed because super creates a reference record where [[Base]] == [[FunctionObject]].[[HomeObject]].

It is related with #4980.

[nicolo-ribaudo]

This test case looks good. It might be worth adding one that is the same but has a set foo(_) {} setter in the base class, and then it should not throw, right?

[nicolo-ribaudo]

Just to double check that I'm understanding correctly. The ReferenceRecord for the lhs is:

• [[Base]]: A.prototype
• [[ReferencedName]]: foo
• [[Strict]]: true
• [[ThisValue]]: ns

In PutValue we call A.prototype.[[Set]](ns, "foo", ...). A.prototype has no "foo", so it calls OrdinarySet(ns, "foo", ...). OrdinarySet calls ns.[[GetOwnProperty]]("foo"), which calls eventually gets ns.foo and throws a ReferenceError.

• If that ReferenceError was not thrown (because foo is not in TDZ) then later when doing the actual Set we get a TypeError.
• If A.prototype had a "foo" setter, we'd call it and exit before throwing the ReferenceError.

I'm approving assuming that my understanding of why this test is like this is correct.

[caiolima]

Just to double check that I'm understanding correctly. The ReferenceRecord for the lhs is:

• [[Base]]: A.prototype
• [[ReferencedName]]: foo
• [[Strict]]: true
• [[ThisValue]]: ns

In PutValue we call A.prototype.[[Set]](ns, "foo", ...). A.prototype has no "foo", so it calls OrdinarySet(ns, "foo", ...). OrdinarySet calls ns.[[GetOwnProperty]]("foo"), which calls eventually gets ns.foo and throws a ReferenceError.

• If that ReferenceError was not thrown (because foo is not in TDZ) then later when doing the actual Set we get a TypeError.
• If A.prototype had a "foo" setter, we'd call it and exit before throwing the ReferenceError.

I'm approving assuming that my understanding of why this test is like this is correct.

Yes. Also, the call to ns.[[GetOwnProperty]]("foo") happens because OrdinarySet calls OrdinarySetWithOwnDescriptor(A.prototype, "foo", ..., ns, null), and A.prototype.[[GetPrototypeOf]]() returns null.

[caiolima]

This test case looks good. It might be worth adding one that is the same but has a set foo(_) {} setter in the base class, and then it should not throw, right?

Makes sense to add such case as well.