Invalid error produced between super and child classes

Flow version: 0.96

## Expected behavior

Correct typing enforced and valid errors produced between super and child classes that together form a React component.

## Actual behavior

An invalid error is reported. Expectation is that flow reports a "missing argument" error on line 15 (refer to try-flow snippet attached) but instead reports "missing property".

Also:
1. the base class requires long winded annotations of the props and state attributes each time these are referenced; ie. `componentDidUpdate(prevProps: P & BaseProps): void`. Is there any way to simplify this?
1. I couldn't make the spread operator work; the form `{ ...P, ...BaseProps }` errors out. Shouldn't this be the preferred form over the intersection operator?

* Link to Try-Flow or Github repo:
[Try-Flow link](https://flow.org/try/#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-lquj9YNsY+qa3VId1WZmZYFnFXpFx2XOGpTQ5hhOa4eGuYgQA)