fix when there are no namespaces defined

Author: withinboredom

Zend/zend_namespaces.c

@@ -96,9 +96,14 @@ zend_class_entry *zend_lookup_namespace(zend_string *name) {
 }
 
 void zend_destroy_namespaces(void) {
-   zend_hash_destroy(EG(namespaces));
-   FREE_HASHTABLE(EG(namespaces));
-   EG(namespaces) = NULL;
-   pefree(EG(global_namespace), 0);
-   EG(global_namespace) = NULL;
+   if (EG(namespaces) != NULL) {
+      zend_hash_destroy(EG(namespaces));
+      FREE_HASHTABLE(EG(namespaces));
+      EG(namespaces) = NULL;
+   }
+
+   if (EG(global_namespace) != NULL) {
+      pefree(EG(global_namespace), 0);
+      EG(global_namespace) = NULL;
+   }
 }