title: Prettier doesn't parse Typescript type cast
body: <p>I'm using Prettier 1.17.1 and TypeScript 3.4.5 with <a href="https://github.com/facebook/create-react-app" rel="nofollow noreferrer">create-react-app</a>.</p>
  
  <p>I'm getting the error below each time I try to use the <code>x as T</code> syntax in TypeScript for type cast:</p>
  
  <pre><code>src/Form.tsx
  [error] src/Form.tsx: SyntaxError: Unexpected identifier (82:57)
  [error]   80 |                 value={data.position}
  [error]   81 |                 onChange={e =&gt; {
  [error] &gt; 82 |                     const nextPosition = e.target.value as Position
  
  </code></pre>
  
  <p>I've tried also a different syntax <code>&lt;T&gt; x</code> but it breaks TS compilation due to the JSX format.</p>