Fix Metadata Caching when it changes in EventListeners

Author: dron-alterpost

lib/Doctrine/Common/Persistence/Mapping/AbstractClassMetadataFactory.php

@@ -36,7 +36,7 @@ abstract class AbstractClassMetadataFactory implements ClassMetadataFactory
     private $loadedMetadata = [];
 
     /** @var string[] */
-    private $aliasesMap = [];
+    protected $aliasesMap = [];
 
     /** @var bool */
     protected $initialized = false;