Description:
------------
Throw exception in __autoload() implementation is impossible. Instead fatal error "Class (...) not found" is reported.

Reproduce code:
---------------
<?php

function loader($class) {
    @include_once($class.'.php');

    if (!class_exists($class, false)) {
        throw new Exception("Class ".$class." not found");
    }
}

spl_autoload_register('loader');

try{
  class FooClass extends Some_Not_Existing_Class {}
}
catch (Exception $e) {
  echo "Caught load class failed exception (".$e->getMessage().").";
}


Expected result:
----------------
Caught load class failed exception (Class Some_Not_Existing_Class not found).

Actual result:
--------------
Fatal error: Class 'Some_Not_Existing_Class' not found in C:\dev\workspace\foo.php on line 19