Cherry picked from commit
d5e4bf920c7.
Change-Id: Ie7c9393c5a77279b9342152b9fdc187f22acf5c0
* (T196185) Don't allow setting $wgDBmysql5 in the installer.
* (T196125) php-memcached 3.0 (provided with PHP 7.0) is now supported.
* (T182366) UploadBase::checkXMLEncodingMissmatch() now works on PHP 7.1+
+* (T118683) Fix exception from &$user deref on HHVM in the TitleMoveComplete hook.
=== Changes since MediaWiki 1.31.0-rc.0 ===
* (T33223) Drop archive.ar_text and ar_flags.