title: Testing with a metaoperator doesn't print the test description
body: <p>I was writing tests on Complex arrays and I was using the <code>Z≅</code> operator to check whether the arrays were approximately equal, when I noticed a missing test description.<br>
  I tried to golf the piece of code to find out the simplest case that shows the result I was seeing. The description is missing in the second test even when I use Num or Int variables and the <code>Z==</code> operator.</p>
  
  <pre><code>use Test;
  
  my @a = 1e0, 3e0;
  my @b = 1e0, 3e0;
  ok @a[0] == @b[0], 'description1';     # prints: ok 1 - description1
  ok @a[^2] Z== @b[^2], 'description2';  # prints: ok 2 -
  
  done-testing;
  </code></pre>
  
  <p>Is there a simple explanation or is this a bug?</p>