title: Why use @babel/polyfill and also report API call errors
body: <p>I am using @babel/polyfill for IE9 compatibility, the project uses react16, but when I use @babel/polyfill, I reported a setProptotypeOf is not a supported property or method, but I saw the packaged code, indeed do For compatibility processing, @babel/polyfill does take effect. Why is this problem still occurring?</p>
  
  <p>react16, @babel/polyfill^7.4.4  webpack^4.19.1 babel^7.0.0</p>
  
  <pre><code> entry: [
    "@babel/polyfill",
    ....
   ]
  </code></pre>
  
  <p>I expected that my project can runing well in IE9</p>