Git commits in Moodle 3.5.4 by Michael Aherne

commit 83c4b6d01e824c1011bf05dc3a2ee00eb88b7ea9
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Tue, 04 Dec 2018 21:01:07 +0800
Tag:    v3.5.4

MDL-64216 privacy: Split query to use indexes.