Don't require rc=1 for function static variables

If file cache only is used, then static_variables_ptr may point
to an immutable static_variables HT, which we do not want to
destroy here.

Author: nikic

Zend/zend_execute_API.c

@@ -287,8 +287,9 @@ void shutdown_executor(void) /* {{{ */
 			if (op_array->static_variables) {
 				HashTable *ht = ZEND_MAP_PTR_GET(op_array->static_variables_ptr);
 				if (ht) {
-					ZEND_ASSERT(GC_REFCOUNT(ht) == 1);
-					zend_array_destroy(ht);
+					if (!(GC_FLAGS(ht) & IS_ARRAY_IMMUTABLE) && GC_DELREF(ht) == 0) {
+						zend_array_destroy(ht);
+					}
 					ZEND_MAP_PTR_SET(op_array->static_variables_ptr, NULL);
 				}
 			}