<!--
  Note: if the issue is about documentation or the website, please file it at:
  https://github.com/reactjs/reactjs.org/issues/new
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**Do you want to request a *feature* or report a *bug*?** Bug, I guess

**What is the current behavior?** 


```
  console.error node_modules/fbjs/lib/warning.js:33
    Warning: Detected multiple renderers concurrently rendering the same context provider. This is currently unsupported.
```

Steps to reproduce the behavior:
1. `git clone https://github.com/stereobooster/react-context-issue`
2. `cd react-context-issue`
3. `yarn`
4. `yarn test`

**What is the expected behavior?** no warning

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?** React 16.4. Browser not affected, because error is in node.js

Open this because of https://github.com/facebook/react/pull/13127#issuecomment-402527012

Issue happens because of Enzyme (https://github.com/airbnb/enzyme/issues/1693), code is unreleased, so I copy-pasted it from master. 

I'm looking for advice or some clue on how to fix this, so I would be able to create PR in Enzyme repo (or in React repo if this is the case). Thank you.


if (!node) {
    return;
  }
  if (Array.isArray(node)) {
    node.forEach(cleanNodeOrArray);
    return;
  }
  if (node && node.instance) {
    node.instance = null;
  }
  if (node && node.props && node.props.children) {
    
    const {children, ...props} = node.props;
    node.props = props;
  }
  if (Array.isArray(node.rendered)) {
    node.rendered.forEach(cleanNodeOrArray);
  } else if (typeof node.rendered === 'object') {
    cleanNodeOrArray(node.rendered);
  }
}
describe('ReactTestRenderer', () => {
  it('renders a simple component', () => {
    function Link() {