Uncovered during @raunofreiberg's select work (#13389).
select._wrapperState.initialValue is only ever assigned, never referenced. Can it be removed?
Example:
https://github.com/facebook/react/blob/master/packages/react-dom/src/client/ReactDOMFiberSelect.js#L191
It would be great if someone could investigate this, and figure out if it can be removed.