title: Array - join and toString calls return an empty string after toLocaleString call
body: <p>I'm not getting the point why calls to the <code>join</code> and <code>toString</code> methods on an Array object return an empty string after a call to <code>toLocaleString</code>:</p>
  
  <pre><code>let A = [1, 2, 3];
  A.toString(); =&gt; "1,2,3"
  A.join(); =&gt; "1,2,3"
  A =&gt; (3) [1, 2, 3]
  A.toLocaleString(); =&gt; ""
  A.toString(); =&gt; ""
  A.join(); =&gt; ""
  A =&gt; (3) [1, 2, 3]
  </code></pre>
  
  <p>I'm trying on Google Chrome 73.0.3683.103, on Firefox I don't experience the same issue.</p>