Unify JoinedSubclassPersister dequeue

Fix JoinedSubclassPersister as BasicEntityPersister was already fixed in GH-10735.

The fix can be verified by modifying UnitOfWork to execute `BasicEntityPersister::executeInserts()` for multiple entities at once for the same entity class/persister instance - https://github.com/doctrine/orm/blob/2.20.3/src/UnitOfWork.php#L1186 - then reproducible on `Doctrine\Tests\ORM\Functional\Ticket\GH10531Test::testInserts` test.

As extending/modifying UnitOfWork in tests in not easily possible, I submit this fix for v2.x without a test.

Author: mvorisek

src/Persisters/Entity/BasicEntityPersister.php

@@ -302,8 +302,8 @@ public function executeInserts()
                 $this->assignDefaultVersionAndUpsertableValues($entity, $id);
             }
 
-            // Unset this queued insert, so that the prepareUpdateData() method knows right away
-            // (for the next entity already) that the current entity has been written to the database
+            // Unset this queued insert, so that the prepareUpdateData() method (called via prepareInsertData() method)
+            // knows right away (for the next entity already) that the current entity has been written to the database
             // and no extra updates need to be scheduled to refer to it.
             //
             // In \Doctrine\ORM\UnitOfWork::executeInserts(), the UoW already removed entities

src/Persisters/Entity/JoinedSubclassPersister.php

@@ -149,7 +149,7 @@ public function executeInserts()
         // Execute all inserts. For each entity:
         // 1) Insert on root table
         // 2) Insert on sub tables
-        foreach ($this->queuedInserts as $entity) {
+        foreach ($this->queuedInserts as $key => $entity) {
             $insertData = $this->prepareInsertData($entity);
 
             // Execute insert on root table
@@ -194,9 +194,16 @@ public function executeInserts()
             if ($this->class->requiresFetchAfterChange) {
                 $this->assignDefaultVersionAndUpsertableValues($entity, $id);
             }
-        }
 
-        $this->queuedInserts = [];
+            // Unset this queued insert, so that the prepareUpdateData() method (called via prepareInsertData() method)
+            // knows right away (for the next entity already) that the current entity has been written to the database
+            // and no extra updates need to be scheduled to refer to it.
+            //
+            // In \Doctrine\ORM\UnitOfWork::executeInserts(), the UoW already removed entities
+            // from its own list (\Doctrine\ORM\UnitOfWork::$entityInsertions) right after they
+            // were given to our addInsert() method.
+            unset($this->queuedInserts[$key]);
+        }
     }
 
     /**