Fix final zpp missmatch failure in DOMDocument::saveXML.

Author: beberlei

ext/dom/dom.stub.php

@@ -159,7 +159,7 @@ public function saveHTMLFile(string $filename) {}
 #endif
 
     /** @return string|false */
-    public function saveXML(?DOMNode $node, int $options = 0) {}
+    public function saveXML(?DOMNode $node = null, int $options = 0) {}
 
 #if defined(LIBXML_SCHEMAS_ENABLED)
     /** @return bool */

ext/dom/dom_arginfo.h

@@ -207,7 +207,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMDocument_saveHTMLFile, 0, 0, 1)
 ZEND_END_ARG_INFO()
 #endif
 
-ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMDocument_saveXML, 0, 0, 1)
+ZEND_BEGIN_ARG_INFO_EX(arginfo_class_DOMDocument_saveXML, 0, 0, 0)
 	ZEND_ARG_OBJ_INFO(0, node, DOMNode, 1)
 	ZEND_ARG_TYPE_INFO(0, options, IS_LONG, 0)
 ZEND_END_ARG_INFO()