Refator array_map into simple loop for performance. (#11332)

Author: beberlei

src/UnitOfWork.php

@@ -1781,18 +1781,15 @@ public function addToIdentityMap($entity)
      */
     final public static function getIdHashByIdentifier(array $identifier): string
     {
+        foreach ($identifier as $k => $value) {
+            if ($value instanceof BackedEnum) {
+                $identifier[$k] = $value->value;
+            }
+        }
+
         return implode(
             ' ',
-            array_map(
-                static function ($value) {
-                    if ($value instanceof BackedEnum) {
-                        return $value->value;
-                    }
-
-                    return $value;
-                },
-                $identifier
-            )
+            $identifier
         );
     }