Git commits in Moodle 3.6.2 by Michael Aherne

commit 3ff4fc8e455be730bc5b10bfb52ddc112f4d8197
Author: Michael Aherne <michael.aherne@strath.ac.uk>
Date:   Tue, 04 Dec 2018 21:01:07 +0800
Tag:    v3.6.2

MDL-64216 privacy: Split query to use indexes.