Description:
------------
---
From manual page: http://www.php.net/migration71.incompatible
---
When "return" without value in a function using return type into PHP 7.0, this will not generate fatale if "return" is not executed.

When migrating to PHP 7.1, it will generate a compilation error "Fatal error: A function with return type must return a value" even if "return" is not executed.

Test script:
---------------
<?php
function foo(): int {
   if (false) { 
      return;
   }
}
?>

Replace the "false" condition by what you want, never or rarely called.