Fix undefined offset when formatting namespace suggestions
Merge branch '2.4'

* 2.4:
  [Debug] fixed unit tests
  Avoid notice from being *eaten* by fatal error.
  Teardown used wrong property
  Modified guessDefaultEscapingStrategy to not escape txt templates
  Fix DateType for 32bits computers.
  Fixed the registration of validation.xml file when the form is disabled
  fixed lexing expression ending with spaces
  Fixes #9633, Removed dependency to Symfony\Bundle\FrameworkBundle\Tests\TestCase
  [Validator] Replaced inexistent interface.
  [HttpKernel] Fix profiler event-listener usage outside request stack context
  When getting the session's id, check if the session is not closed
  Fix undefined offset when formatting namespace suggestions
  Adjusting CacheClear Warmup method to namespaced kernels