Merge branch '5.2' into 5.x

* 5.2: (23 commits)
  [Console] Fix Windows code page support
  [SecurityBundle] Allow ips parameter in access_control accept comma-separated string
  [Form] Add TranslatableMessage support to choice_label option of ChoiceType
  Remove code that deals with legacy behavior of PHP_Incomplete_Class
  [Config][DependencyInjection] Uniformize trailing slash handling
  [PropertyInfo] Make ReflectionExtractor correctly extract nullability
  [PropertyInfo] fix attribute namespace with recursive traits
  [PhpUnitBridge] Fix tests with `@doesNotPerformAssertions` annotations
  Check redis extension version
  [Security] Update Russian translations
  [Notifier] Fix return SentMessage then Messenger not used
  [VarExporter] Add support of PHP enumerations
  [Security] Added missing Japanese translations
  [Security] Added missing Polish translations
  [Security] Add missing Italian translations #41051
  [Security] Missing translations pt_BR
  getProtocolVersion may return null
  Fix return type on isAllowedProperty method
  Make FailoverTransport always pick the first transport
  [TwigBridge] Fix HTML for translatable custom-file label in Bootstrap 4 theme
  ...

Author: nicolas-grekas

Exception/FlattenException.php

@@ -359,7 +359,6 @@ private function flattenArgs(array $args, int $level = 0, int &$count = 0): arra
                 return ['array', '*SKIPPED over 10000 entries*'];
             }
             if ($value instanceof \__PHP_Incomplete_Class) {
-                // is_object() returns false on PHP<=7.1
                 $result[$key] = ['incomplete-object', $this->getClassNameFromIncomplete($value)];
             } elseif (\is_object($value)) {
                 $result[$key] = ['object', \get_class($value)];