Enables serialization of errors, specifically, DOMException, Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, and URIError. An example of where this capability may be used is to pass an Error to a worker using PostMessage().
The primary motivation is Transferable Streams. For example, when we see a read error, we need to pass the error to the remote end.
Docs: https://github.com/whatwg/html/pull/4665 https://github.com/heycam/webidl/pull/732
Explainers: https://github.com/whatwg/html/issues/4268