title: Powershell array is not cleared
body: <p>My source code:</p>
  
  <pre class="lang-js prettyprint-override"><code># $arr = @(); results in same behaviour
  $arr = New-Object System.Collections.ArrayList;
  
  $arr.Count;
  $arr += "z";
  
  $arr.Count;
  $arr.Clear();
  $arr.Count;
  </code></pre>
  
  <p>Output:</p>
  
  <blockquote>
    <p>0<br />
    1<br />
    1</p>
  </blockquote>