title: Property 'formatToParts' does not exist on type 'DateTimeFormat'
body: <p>I am using angular 9 with a tsconfig set to es6.</p>
  
  <pre><code>    "target": "es6",
      "lib": [
        "es6",
        "dom"
      ]
  </code></pre>
  
  <p>I am trying to do the following :</p>
  
  <pre><code>    static formatForDisplay(date: Date): string {
          const dtf = new Intl.DateTimeFormat('en', { year: 'numeric', month: 'short', day: '2-digit' });
          const [{ value: mo }, , { value: da }, , { value: ye }] = dtf.formatToParts(date);
          return `${mo} ${da}, ${ye}`;
      }
  </code></pre>
  
  <p>but typescript complain about when I compile (but not in visual code)</p>
  
  <blockquote>
    <p>Property 'formatToParts' does not exist on type 'DateTimeFormat'</p>
  </blockquote>
  
  <p>why so? it does exist </p>