Description:
------------
It seems that calling the DateTime class constructor causes an error
accumulated in error_get_last() to be cleared.

I am using a 64bit Linux (Ubuntu 9.10) with PHP 5.2.11 built by
dotdeb.org (unfortunately phpinfo() of their version doesn't give up
configure options). The problem reproduces with a default php.ini,
both as Apache module and on CLI.

I was also able do reproduce this on another system with another PHP
version (5.2.9, also a dotdeb build).

Reproduce code:
---------------
@trigger_error('foo');
echo (is_array(error_get_last())?'Error':'No error') . "\n";

$dt = new DateTime();
echo (is_array(error_get_last())?'Error':'No error') . "\n";

Expected result:
----------------
Error
Error


Actual result:
--------------
Error
No error