function isHttpError(e, status) {
	if (!(e instanceof HttpError)) return false;
	return !status || e.status === status;
}
Checks whether this is an error thrown by {@link error}.
@template {number} T
@param {unknown} e
@param {T} [status] The status to filter for.
@return {e is (HttpError & { status: T extends undefined ? never : T })}