Description:
------------
On some circumstances it's possible to get a wrong integer value on casting from float.

I can reproduce this bug with the following installations:
php -v
PHP 5.3.10-1ubuntu3.6 with Suhosin-Patch (cli) (built: Mar 11 2013 14:34:31) 
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies
    with Xdebug v2.1.0, Copyright (c) 2002-2010, by Derick Rethans

./sapi/cli/php -v
PHP 5.6.0-dev (cli) (built: Mar 17 2013 22:02:54) 
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.6.0-dev, Copyright (c) 1998-2013 Zend Technologies

Test script:
---------------
// this works
$v = (float) 6;
var_dump($v, (int)$v);

// this is wrong
$v = log(64, 2);
var_dump($v, (int)$v);

Expected result:
----------------
float(6)
int(6)
float(6)
int(6)


Actual result:
--------------
float(6)
int(6)
float(6)
int(5)