Git commits in Moodle 3.11.x by Jonathon Fowler

commit f2c9e1728e15e1a9996f1193d8e47dd7ad08ae95
Author: Jonathon Fowler <fowlerj@usq.edu.au>
Date:   Wed, 05 May 2021 14:35:52 +0800
Tag:    v3.11.1

MDL-60431 qtype_calculated: handle NAN and INF calculation outcomes