Git commits in Moodle 3.7.6 by Dani Palou

commit 3ec126df580343a1458e8fc85b31fa231368bc75
Author: Dani Palou <dani@moodle.com>
Date:   Thu, 05 Mar 2020 18:47:35 +0800
Tag:    v3.7.6

MDL-67189 external: Add test to catch PHP exceptions

commit 59964c5c95c15121ca589ea77ca038d0a8def1b7
Author: Dani Palou <dani@moodle.com>
Date:   Wed, 12 Feb 2020 17:14:52 +0800
Tag:    v3.7.6

MDL-67189 external: Catch Throwable in call_external_function