Fix persisting property info table with internal parent

If the property info comes from an internal parent, we won't have
an xlat entry for it. Leave it alone in that case.

Author: nikic

ext/opcache/tests/preload.inc

@@ -51,6 +51,13 @@ class TraitAliasTest {
     }
 }
 
+// Create reference to a property declared in an internal parent class.
+class MyException extends Exception {
+    public function __construct($message) {
+        $this->message =& $message;
+    }
+}
+
 function get_anon() {
     return new class {};
 }

ext/opcache/tests/preload_prop_info_table.phpt

@@ -0,0 +1,19 @@
+--TEST--
+Preloading of the property info table with internal parent
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.optimization_level=-1
+opcache.preload={PWD}/preload.inc
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+if (PHP_OS_FAMILY == 'Windows') die('skip Preloading is not supported on Windows');
+?>
+--FILE--
+<?php
+$e = new MyException("foo");
+echo $e->getMessage(), "\n";
+?>
+--EXPECT--
+foo

ext/opcache/zend_persist.c

@@ -914,8 +914,11 @@ static void zend_persist_class_entry(zval *zv)
 
 			for (i = 0; i < ce->default_properties_count; i++) {
 				if (ce->properties_info_table[i]) {
-					ce->properties_info_table[i] = zend_shared_alloc_get_xlat_entry(
+					zend_property_info *prop_info = zend_shared_alloc_get_xlat_entry(
 						ce->properties_info_table[i]);
+					if (prop_info) {
+						ce->properties_info_table[i] = prop_info;
+					}
 				}
 			}
 		}