Safari 10 read only error

When running the polyfill on Safari 8-10 we are getting on this line:
this.isIntersecting = !!entry.intersectionRect;

TypeError: Attempted to assign to readonly property.

Thanks

[graemeenglish]

This also causes problems on chrome 94 and edge 94 when forcing the polyfill for testing using

<script> delete window.IntersectionObserver; delete window.IntersectionObserverEntry; </script>

[miketaylr]

The polyfill is being removed in #499 (see #433 for discussion).

If you can still reproduce bugs in the native implementations, filing bugs in the various bug tracks would be really helpful.

I'm going to close this as wontfix, but thanks for taking the time to report this issue!