Observed this on react@16.0.0-beta.5

```js
import React from 'react';
import { renderToString } from 'react-dom/server';

const B = () => 'b';

console.log(renderToString(<div>{'a'}<B />{'c'}</div>));
```

This renders as `<div data-reactroot="">a<!-- -->bc</div>`. If you try to hydrate this you'll get the error: Text content did not match. Server: "bc" Client: "b".
warnNoop(publicInstance, 'setState');
          return null;
        }
        queue.push(partialState);
      },
    };
    if (shouldConstruct(Component)) {
      inst = new Component(child.props, publicContext, updater);
    } else {
      inst = Component(child.props, publicContext, updater);
      if (inst == null || inst.render == null) {
        child = inst;
        validateRenderResult(child, Component);
        continue;
      }
    }
    inst.props = child.props;
    inst.context = publicContext;
    inst.updater = updater;
    var initialState = inst.state;
    if (initialState === undefined) {
      inst.state = initialState = null;
    }
    if (inst.componentWillMount) {
      inst.componentWillMount();
      if (queue.length) {
        var oldQueue = queue;
        var oldReplace = replace;
        queue = null;
        replace = false;