Merge branch '4.4' into 5.4

* 4.4:
  [HttpKernel] lock when writting profiles
  Using identical comparison for path validation
  [Mime] Fix email rendering when having inlined parts that are not related to the content
  [HttpFoundation] move flushing outside of Response::closeOutputBuffers
  [FrameworkBundle] Do not throw when describing a factory definition
  Fix checking result of DateTime::getLastErrors

Author: nicolas-grekas

Response.php

@@ -399,6 +399,7 @@ public function send()
             litespeed_finish_request();
         } elseif (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
             static::closeOutputBuffers(0, true);
+            flush();
         }
 
         return $this;
@@ -1245,7 +1246,6 @@ public static function closeOutputBuffers(int $targetLevel, bool $flush): void
         while ($level-- > $targetLevel && ($s = $status[$level]) && (!isset($s['del']) ? !isset($s['flags']) || ($s['flags'] & $flags) === $flags : $s['del'])) {
             if ($flush) {
                 ob_end_flush();
-                flush();
             } else {
                 ob_end_clean();
             }