title: Some properties of the global instance are not copied by spread operator or by Object.assign in node v12
body: <p>With node version 8 and version 10, this code works fine:</p>
  
  <pre><code>const cpGlobal = {...global};
  assert(typeof cpGlobal.Buffer === "function")
  </code></pre>
  
  <p>The same code with node v12.13.1 doesn't work. <code>cpGlobal.Buffer</code> is <code>undefined</code>, it is not copied from the original <code>global</code>. I have tried also <code>Object.assign</code> with the same result.</p>
  
  <p>The same happen for other properties, like <code>process</code>. Some properties are copied correctly, like <code>setImmediate</code>, <code>setInterval</code>, ...</p>
  
  <p>Why?</p>