Description:
------------
I suggest changing get_functions_defined() function to have flag/option to return user function by includes/requires.

Example:

#require1.php
<?php
  function one()
  {
      return 1;
  }
  function two()
  {
      return 2;
  }
?>

#require2.php
<?php
  function three()
  {
      return 3;
  }
  function four()
  {
      return 4;
  }
?>

#main code
<?php
  require_once('require1.php');
  require_once('require2.php');
  
  $fn_arr = get_functions_defined(true);	// true - is enabled return user function by
  											// includes and requires.
  print_r($fn_arr); 
?>

Output result:

Array ( [internal] => Array (
                               ...
),
        [user] => Array (
                            [require1.php] => Array ([0] => 'one', [1] => 'two'),
                            [require2.php] => Array ([0] => 'three', [1] => 'four'),
))