title: unexpected T_OBJECT_OPERATOR but no TypeChecker errors (Hacklang)
body: <pre><code>&lt;?hh //strict 
  </code></pre>
  
  <hr>
  
  <pre><code>foreach ($list as $id) {
      $items = new DestinationsByCountry($id);
      $remapped = $items-&gt;byKey('destination_id')-&gt;map($stringed ==&gt; (int) $stringed);
      $this-&gt;ids-&gt;addAll($remapped);
  }
  </code></pre>
  
  <hr>
  
  <pre><code>foreach ($list as $id) {
      $this-&gt;ids-&gt;addAll(
          // ******* error line below *******
          new DestinationsByCountry($id)
              -&gt;byKey('destination_id')
              -&gt;map($stringed ==&gt; (int) $stringed)
      );
  }
  </code></pre>
  
  <p>Both is OK for the typecheker, but the second cause fatal error </p>
  
  <blockquote>
    <p>Fatal error: syntax error, unexpected T_OBJECT_OPERATOR, expecting ')' </p>
  </blockquote>