Merge branch '6.4' into 7.0

* 6.4: (28 commits)
  [Serializer] Fix `@method` annotation
  fix compatibility with Doctrine DBAL 4
  ensure string type with mbstring func overloading enabled
  [HttpKernel] Fix quotes expectations in tests
  [Validator] updated Greek translation
  [Cache][HttpFoundation][Lock] Fix empty username/password for PDO PostgreSQL
  [HttpClient][WebProfilerBundle] Do not generate cURL command when files are uploaded
  render newline in front of all script elements
  fix test fixture
  fix tests
  [Cache] Fix property types in PdoAdapter
  PHP files cannot be executable without shebang
  [TwigBridge] Mark CodeExtension as @internal
  Remove full DSNs from exception messages
  [Yaml] Fix uid binary parsing
  Disable the "Copy as cURL" button when the debug info are disabled
  [HttpClient] Replace `escapeshellarg` to prevent overpassing `ARG_MAX`
  Fix missing `profile` option for console commands
  [HttpFoundation][Lock] Makes MongoDB adapters usable with `ext-mongodb` only
  [HttpKernel] Preventing error 500 when function putenv is disabled
  ...

Author: nicolas-grekas

Extension/CodeExtension.php

@@ -18,7 +18,12 @@
 /**
  * Twig extension relate to PHP code and used by the profiler and the default exception templates.
  *
+ * This extension should only be used for debugging tools code
+ * that is never executed in a production environment.
+ *
  * @author Fabien Potencier <[email protected]>
+ *
+ * @internal
  */
 final class CodeExtension extends AbstractExtension
 {