Merge branch '3.4' into 4.3

* 3.4:
  CS
  [Serializer] Skip uninitialized (PHP 7.4) properties in PropertyNormalizer and ObjectNormalizer
  stop using deprecated Doctrine persistence classes
  Fix regex lookahead syntax in ApplicationTest
  [SecurityBundle][FirewallMap] Remove unused property
  [DI] Improve performance of processDefinition
  Fix invalid Windows path normalization
  [Validator][ConstraintValidator] Safe fail on invalid timezones
  [DoctrineBridge] Fixed submitting invalid ids when using queries with limit
  fix comparisons with null values at property paths

Author: nicolas-grekas

Compiler/ResolveInstanceofConditionalsPass.php

@@ -63,9 +63,10 @@ private function processDefinition(ContainerBuilder $container, $id, Definition
         $instanceofTags = [];
         $instanceofCalls = [];
         $instanceofBindings = [];
+        $reflectionClass = null;
 
         foreach ($conditionals as $interface => $instanceofDefs) {
-            if ($interface !== $class && (!$container->getReflectionClass($class, false))) {
+            if ($interface !== $class && !(null === $reflectionClass ? $reflectionClass = ($container->getReflectionClass($class, false) ?: false) : $reflectionClass)) {
                 continue;
             }