Merge branch '3.4' into 4.4

* 3.4:
  Disable the PhpUnit bridge when testing it
  [PropertyInfo] Support for the mixed type.
  [Form] Add Bosnian (bs) validators translation
  [Form] Add missing Serbian (latn & cyrl) validators translation
  [Form] [Validator] added pt_BR translations
  Estonian update
  [PhpUnitBridge] fix running parallel tests with phpunit 9
  [VarDumper] fix truncating big arrays

Author: nicolas-grekas

bin/simple-phpunit.php

@@ -264,11 +264,11 @@ class SymfonyExcludeListPhpunit {}
 if (method_exists('PHPUnit\Util\ExcludeList', 'addDirectory')) {
     (new PHPUnit\Util\Excludelist())->getExcludedDirectories();
     PHPUnit\Util\ExcludeList::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListPhpunit'))->getFileName()));
-    PHPUnit\Util\ExcludeList::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListSimplePhpunit'))->getFileName()));
+    class_exists('SymfonyExcludeListSimplePhpunit', false) && PHPUnit\Util\ExcludeList::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListSimplePhpunit'))->getFileName()));
 } elseif (method_exists('PHPUnit\Util\Blacklist', 'addDirectory')) {
     (new PHPUnit\Util\BlackList())->getBlacklistedDirectories();
     PHPUnit\Util\Blacklist::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListPhpunit'))->getFileName()));
-    PHPUnit\Util\Blacklist::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListSimplePhpunit'))->getFileName()));
+    class_exists('SymfonyExcludeListSimplePhpunit', false) && PHPUnit\Util\Blacklist::addDirectory(\dirname((new \ReflectionClass('SymfonyExcludeListSimplePhpunit'))->getFileName()));
 } else {
     PHPUnit\Util\Blacklist::$blacklistedClassNames['SymfonyExcludeListPhpunit'] = 1;
     PHPUnit\Util\Blacklist::$blacklistedClassNames['SymfonyExcludeListSimplePhpunit'] = 1;