Function type hints for LinkHolderArray.php

Change-Id: I5e429baab774a790b3558732f9c87637adfbe4ce
Setup.php: Move hacky skin requires higher up

Some of the setup code in some of the configurations apparently depends
on all extensions and skins being already required by the point
Setup.php is being loaded. We ran into issues with LocalisationCache.

Bug: 67318
Change-Id: Idde13c2e835a9969593a4716a62b392d4c1388d6
Merge "Function type hints for LinkHolderArray.php"
Merge "Setup.php: Move hacky skin requires higher up"