Merge branch 'PHP-7.1' of git.php.net:php-src into PHP-7.1

* 'PHP-7.1' of git.php.net:php-src: (134 commits)
  fix useless assignment
  avoid needless function call
  remove useless assignment
  remove unused assignment
  rewrite the getcwd part
  fix leak
  fix unused assignment
  remove duplicated symbol
  Revert 	39587c4817522f40a639f32f77f49595fab066f9 	8b7f594a2bcd67154274c5533274fe4d83a676fd Because of 	24fdffdacbfeaa20e8f08d44c7c61e3fb7ba9ac5
  add extra test to protected behavior of compact and array string key order
  fix unintentional bc break with compact('this') behavior
  Fix some grammatical errors in PHP 7.1 Upgrade Notes
  Update NEWS
  Fixed bug #72982 (Memory leak in zend_accel_blacklist_update_regexp() function)
  Update NEWS and UPGRADING
  Revert "Revert "Implement RFC Add session_gc() https://wiki.php.net/rfc/session-gc""
  Revert "Revert "Merge RFC https://wiki.php.net/rfc/session-create-id""
  Revert "Revert "Add tests""
  Revert "Fix NEWS"
  Fix bug #72940 properly. Reduce needless branches
  ...