Merge branch '4.4' into 5.1

* 4.4:
  quote all dumped unicode spaces
  Switched from parent type hard-coded FQCN to `::class` keyword.

Author: fabpot

Form/Type/DoctrineType.php

@@ -23,6 +23,7 @@
 use Symfony\Component\Form\ChoiceList\ChoiceList;
 use Symfony\Component\Form\ChoiceList\Factory\CachingFactoryDecorator;
 use Symfony\Component\Form\Exception\RuntimeException;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
@@ -239,7 +240,7 @@ abstract public function getLoader(ObjectManager $manager, $queryBuilder, string
 
     public function getParent()
     {
-        return 'Symfony\Component\Form\Extension\Core\Type\ChoiceType';
+        return ChoiceType::class;
     }
 
     public function reset()