We used to throw if event listener is not a function in Stack:

```js
ReactDOM.render(
  <h1 onClick={{}}>Hello World!</h1>,
  document.getElementById('container')
);
```

<img width="565" alt="screen shot 2017-08-08 at 3 41 08 pm" src="https://user-images.githubusercontent.com/810438/29077502-2646412e-7c50-11e7-8c99-3b7f6c0a2589.png">

Fiber silently ignores this.

I think we should throw. This would let us add support for objects (e.g. for passive listener configuration) if we want to in a minor rather than a major.
render() {
          return <table>{this.props.children}</table>;
        }
      }
      class FancyTable extends React.Component {
        render() {
          return <Table>{this.props.children}</Table>;
        }
      }
      function Viz1() {
        return <table><FancyRow /></table>;
      }
      function App1() {
        return <Viz1 />;
      }
      ReactTestUtils.renderIntoDocument(<App1 />);
      expectDev(console.error.calls.count()).toBe(1);
      expectDev(
        normalizeCodeLocInfo(console.error.calls.argsFor(0)[0]),
      ).toContain(
        ReactDOMFeatureFlags.useFiber
          ? '\n    in tr (at **)' +
              '\n    in Row (at **)' +
              '\n    in FancyRow (at **)' +
              '\n    in table (at **)' +
              '\n    in Viz1 (at **)'
          : 'See Viz1 > table > FancyRow > Row > tr.',
      );
      function Viz2() {