title: TypeScript: cannot find name async/await
body: <p>I'm using <code>typescript@next</code> and I want to compile my code to <code>es5</code>, but each time I'm using <code>async</code> or <code>await</code> keywords the compiler errors with that message:</p>
  
  <pre><code>Cannot find name 'await'.
  </code></pre>
  
  <p>Heres my libs: <code>dom</code>, <code>es2015</code>, <code>es2016</code>, <code>es2017</code>.</p>
  
  <p>Code example:</p>
  
  <pre><code>let asyncFn = () =&gt; {
     return new Promise((resolve:Function)=&gt;{resolve(2)})
  }
  // should log `2`
  console.log(await asyncFn())
  </code></pre>
  
  <p>Such things are possible even with <code>typescript@2.0.x</code>, I've tried it, but somehow I am unable to compile my code anyway.</p>