Merge branch '2.7' into 2.8

* 2.7:
  [Yaml] release memory after parsing
  [HttpFoundation] Fix and test status codes according to IANA's data
  Add `use_strict_mode` in validOptions for session
  [Console] Inherit phpdoc from OutputFormatterInterface

Author: nicolas-grekas

Parser.php

@@ -86,6 +86,12 @@ public function parse($value, $exceptionOnInvalidType = false, $objectSupport =
             mb_internal_encoding($mbEncoding);
         }
 
+        $this->lines = array();
+        $this->currentLine = '';
+        $this->refs = array();
+        $this->skippedLineNumbers = array();
+        $this->locallySkippedLineNumbers = array();
+
         if (null !== $e) {
             throw $e;
         }