Merge branch '3.4' into 4.2

* 3.4:
  [Phpunit] fixed support for PHP 5.3
  Response prepare method update
  [Workflow] Added missing license header
  Check if Client exists when test.client does not exist, to provide clearer exception message
  [Form] Preventing validation of children if parent with Valid constraint has no validation groups
  [Tests] fixed compatbility of assertEquals(): void
  [Intl] Fix test
  [Validator] Add the missing translations for the Arabic (ar) locale
  [Intl] Add compile binary
  [Form] Fixed some phpdocs

Author: fabpot

bin/simple-phpunit

@@ -74,11 +74,11 @@ if ('phpdbg' === PHP_SAPI) {
     $PHP .= ' -qrr';
 }
 
-$defaultEnvs = [
+$defaultEnvs = array(
     'COMPOSER' => 'composer.json',
     'COMPOSER_VENDOR_DIR' => 'vendor',
     'COMPOSER_BIN_DIR' => 'bin',
-];
+);
 
 foreach ($defaultEnvs as $envName => $envValue) {
     if ($envValue !== getenv($envName)) {