minor #18021 Don't use reflections when possible (Ener-Getick)

This PR was merged into the 2.3 branch.

Discussion
----------

Don't use reflections when possible

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

Use php functions instead of reflection when possible (to improve a bit the performance).

Commits
-------

a46270a Don't use reflections when possible

Author: fabpot

Mapping/PropertyMetadata.php

@@ -45,12 +45,11 @@ public function getPropertyValue($object)
      */
     protected function newReflectionMember($objectOrClassName)
     {
-        $class = new \ReflectionClass($objectOrClassName);
-        while (!$class->hasProperty($this->getName())) {
-            $class = $class->getParentClass();
+        while (!property_exists($objectOrClassName, $this->getName())) {
+            $objectOrClassName = get_parent_class($objectOrClassName);
         }
 
-        $member = new \ReflectionProperty($class->getName(), $this->getName());
+        $member = new \ReflectionProperty($objectOrClassName, $this->getName());
         $member->setAccessible(true);
 
         return $member;