Git commits in Moodle 3.3.6 by sam marshall

commit 37acf2d4bee66e43df03974f3dd67ba49a376b8d
Author: sam marshall <s.marshall@open.ac.uk>
Date:   Thu, 19 Apr 2018 01:03:25 +0800
Tag:    v3.3.6

MDL-62042 core_search: Unicode non-characters cause indexing problems