- Fix tests (atm preg_match() is wrong)

ext/spl/tests/dit_001.phpt

@@ -1,9 +1,12 @@
 --TEST--
 SPL: Problem with casting to string
+--SKIPIF--
+<?php if (!extension_loaded("spl")) print "skip"; ?>
 --FILE--
 <?php
 $d = new DirectoryIterator('.');
 var_dump($d);
+var_dump(is_string($d));
 preg_match('/x/', $d);
 var_dump(is_string($d));
 ?>
@@ -11,5 +14,6 @@ var_dump(is_string($d));
 --EXPECTF--
 object(DirectoryIterator)#%d (0) {
 }
-bool(true)
+bool(false)
+bool(false)
 ===DONE===