LibJS: Yield looses scheduled/saved exceptions

[Hendiadyoin1]

Reproducer (js test):

function* g() {
    try {
        throw 1;
    } finally {
        yield 0;
    }
}

a = g();
console.log(a.next()); // { "value": 0, "done": false } from the finalizer
expect(a.next).toThrow();

Cause:
Yield::execute_impl calls interpreter.do_return(value) which clears the current exception, which means the finally will not pick it up when execution continues.
But not clearing the exception would instead shadow the return value and bubble up the exception on the first iteration,
so we need to find a way to save the exception in the generator state and restore in on re-entry