Merge branch '4.4'

* 4.4:
  Properly handle optional tag attributes for !tagged_iterator
  [Mime] rename Headers::getAll() to all()
  [Mailer] Fix phpdoc for variadic methods
  [DI] Move non removing compiler passes to after removing passes
  [Process] Deprecate Process::inheritEnvironmentVariables()
  [HttpClient] fix debug output added to stderr at shutdown

Author: nicolas-grekas

Tests/DependencyInjection/DebugExtensionTest.php

@@ -86,6 +86,7 @@ private function compileContainer(ContainerBuilder $container)
     {
         $container->getCompilerPassConfig()->setOptimizationPasses([]);
         $container->getCompilerPassConfig()->setRemovingPasses([]);
+        $container->getCompilerPassConfig()->setAfterRemovingPasses([]);
         $container->compile();
     }
 }