Description:
------------
When I use set_exception_handler() and attempt to create an instance of a class inside the handler (the class is not yet loaded and needs to be loaded with __autoload) - I get crashes.

The crash type depends on whether I use __autoload() or spl_autoload_register(). I the first case I get "Fatal error: Exception thrown without a stack frame in Unknown on line 0", while in the second I get "Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 72 bytes) in /home/vbolshov/tmp/x.php on line 21
Segmentation fault"

It must be noticed, that in case the class already had been loaded by the moment of the exception throw - there are no errors and everything is ok.

I am terribly sorry the the reproduce code is longer than 20 lines but it is really simple and I think it shows all the problems.

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

/*
Uncomment handler class declaration to get rid of crashes
*/

/*
class handler {
        function handle($e) {
                echo $e->getMessage()."\n";
        }
}
*/

function au($class) {
        eval('class handler {
                  function handle($e) {
                      echo $e->getMessage()."\n";
                  }
              }');
}

/*
Uncomment __autoload() and comment spl_autoload_register() call to switch between crash types
*/

/*
function __autoload($class) {
        au($class);
}
*/

spl_autoload_register('au');

set_exception_handler(function($exception) {
        $h = new handler();
        $h->handle($exception);
});

throw new Exception('exception');

Expected result:
----------------
exception

Actual result:
--------------
In case we use spl_autoload_register:
--
Fatal error: Exception thrown without a stack frame in Unknown on line 0
--

In case we use __autoload:
--
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 72 bytes) in /home/vbolshov/tmp/x.php on line 21
Segmentation fault
--

Works ok when handler class declaration at the top is uncommented.