These functions actually does not return anything, so the @return is
wrong here. '@return void' is ignored.
Change-Id: I11495ee05b943c16c1c4715d617c8b50de22276c
Strings like "5.6.99-hhvm" are not version numbers but merely
a way for HHVM to pass version checks. They should not be
displayed in the UI.
This affects Special:Version, the API (action=query&meta=siteinfo),
the installer welcome page, and the debug toolbar.
Follows-up d09ab9001f.
Change-Id: Ia99dca64779e9c4eaddf5f0e0101674d029b8d55