Merge branch '4.4' into 5.0

* 4.4:
  [DependencyInjection] Fix binding tagged services to containers
  [ProxyManager] fix generating proxies for root-namespaced classes
  [DI] skip looking for config class when the extension class is anonymous
  Fix typo
  Docs - Update debug section of UPGRADE guides for 4.4 and 5.0 versions.
  [Dotenv] FIX missing getenv
  [HttpFoundation] fix pdo session handler for sqlsrv
  [HttpClient][Psr18Client] Remove Psr18ExceptionTrait
  [HttpKernel] ignore failuresgenerated by opcache.restrict_api

Author: nicolas-grekas

Kernel.php

@@ -471,7 +471,7 @@ public function write(string $content, array $metadata = null)
                             }
 
                             if (\function_exists('opcache_invalidate') && filter_var(ini_get('opcache.enable'), FILTER_VALIDATE_BOOLEAN)) {
-                                opcache_invalidate($this->getPath(), true);
+                                @opcache_invalidate($this->getPath(), true);
                             }
                         }