title: Difference in matching end of line with PHP regex
body: <p>Given the code:</p>
  <pre><code>$my_str = '
  Rollo is*
  My dog*
  And he\'s very*
  Lovely*
  ';
  
  preg_match_all('/\S+(?=\*$)/m', $my_str, $end_words);
  print_r($end_words);
  </code></pre>
  <p>In PHP 7.3.2 (<a href="https://en.wikipedia.org/wiki/XAMPP" rel="nofollow noreferrer">XAMPP</a>) I get the unexpected output</p>
  <pre><code>Array ( [0] =&gt; Array ( ) )
  </code></pre>
  <p>Whereas in <a href="http://phpfiddle.org" rel="nofollow noreferrer">PhpFiddle</a>, on PHP 7.0.33, I get what I expected:</p>
  <pre><code>Array ( [0] =&gt; Array ( [0] =&gt; is [1] =&gt; dog [2] =&gt; very [3] =&gt; Lovely ) )
  </code></pre>
  <p>Why am I getting this difference? Did something change in regular expression behaviour after 7.0.33?</p>