title: @vue-cli upgrade issues with stencil js web components
body: <p>I use stencilJS web components in Vue via <code>npm link</code>. Recently upgraded to latest version of webpack using <code>@vue-cli upgrade</code>.</p>
  <p>This is now causing errors when the the components are accessed using <code>npm link</code>.
  Getting errors for each web-components in repository.</p>
  <pre><code>ERROR in ../../web-components/loader/index.js 1:0-48
  Module not found: Error: Can't resolve 'core-js/modules/es.object.to-string.js' in 
  'C:\Users\parag\web-components\loader'
  @ ./src/main.ts 11:0-92 18:0-14 19:2-22
  </code></pre>
  <p>Steps I followed so far</p>
  <ol>
  <li><p>npm cache cleared &amp; tried with fresh <code>npm install</code></p>
  </li>
  <li><p>re-installed <code>core-js</code> module.</p>
  </li>
  <li><p>resolved extensions <code>extensions: ['.js', '.jsx', '.ts', '.tsx']</code></p>
  </li>
  <li><p>Setup rule for <code>.js</code> extension in <code>webpack</code>.</p>
  <pre><code> test: /\.js?$/,
   use: { loader: 'babel-loader' },
     exclude: /node_modules/,
   }
  </code></pre>
  </li>
  </ol>
  <p>This is still not working. Kindly guide.</p>