Currently, Mediawiki can use a swift backend to store files. Out of the box, without any provision for larger objects, swift is able to save file up to 5 GB.
A filesize limit currently exists at 2^32 (4 Gb).
It would be convenient to allow MediaWiki to store until 5 Gb when the swift backend is used.
For that, we should ensure file sizes are stored as a 64 bits integer, not as a 32 one.