Description:
------------
When evaluating an instantiated object with "!=" the result is incorreclty returned as false;

Reproduce code:
---------------
echo phpversion();
class foo {
    var $test;
}

$obj = new foo();

if( $obj != null ) {
    echo "\n\ncorrect";
} else {
    echo "\n\nnot correct";
}

Expected result:
----------------
D:\tmp>"c:\Program Files\PHP514\php.exe" obj_null.php
5.1.4

correct

Actual result:
--------------
D:\tmp>php obj_null.php
5.2.0-dev

not correct