Fixed IBM DB2 Platform to support locking

lib/Doctrine/DBAL/Platforms/DB2Platform.php

@@ -513,4 +513,9 @@ class DB2Platform extends AbstractPlatform
     {
         return strtoupper($column);
     }
+
+    public function getForUpdateSQL()
+    {
+        return ' WITH RR USE AND KEEP UPDATE LOCKS';
+    }
 }
\ No newline at end of file

tests/Doctrine/Tests/ORM/Functional/Locking/LockAgentWorker.php

@@ -101,6 +101,7 @@ class LockAgentWorker
         $cache = new \Doctrine\Common\Cache\ArrayCache();
         $config->setMetadataCacheImpl($cache);
         $config->setQueryCacheImpl($cache);
+        $config->setSQLLogger(new \Doctrine\DBAL\Logging\EchoSQLLogger());
 
         $em = \Doctrine\ORM\EntityManager::create($conn, $config);