Description:
------------
lot of php3 codes begin include files by a
  if(defined(..)) return; define(..)
to simulate include_once behavior

it works fine with php4, but with php5, functions
declared after this return raise "cannot redeclare" error
when the file is included twice.


Reproduce code:
---------------
t1.php :
<?php
include("t2.php");
toto();
include("t2.php");
toto();
?>

t2.php :
<?php
error_log("in t2");

if (defined("_T2_INCLUDED")) {
  error_log("already went there");
  return;
}
define("_T2_INCLUDED", "1");

error_log("still in t2");

function toto() {
  echo "Here am I !!\n";
}
?>


Expected result:
----------------
with php4 :
in t2
still in t2
Here am I !!
in t2
already went there
Here am I !!


Actual result:
--------------
with php5 :
in t2
still in t2
Here am I !!

Fatal error: Cannot redeclare toto() (previously declared in t2.php:13) in t2.php on line 14