When I implemented the ability to abort synchronoulsy in flight I made
it possible for erroring async server components to cause an unhandled
rejection error. In the current implementation if you abort during the
synchronous phase of a Function Component and then throw an error in the
synchronous phase React will not attach any promise handlers because it
short circuits the thenable treatment and throws an AbortSigil instead.
This change updates the rendering logic to ignore the rejecting
component.