Description:
------------
I'm doing a multiplataform software. I always need to set set_time_limit(0), but some unix disable then turning on safe_mode. in safe_mode, some functions and functionales are disabled. how can call function_exists("set_time_limit") to test if always i get TRUE? in safe_mode should be false. The same happens with get_defined_functions, that returns an array with set_time_limit seted TRUE.

Reproduce code:
---------------
$bol_result = function_exists("set_time_limit");
if($bol_result)
{
	set_time_limit(0);
}

Expected result:
----------------
$bol_result return false

Actual result:
--------------
$bol_result returns true, then call set_time_limit, my php is in safe_mode so crash:
set_time_limit(): Cannot set time limit in safe mode