Tests: fail automated tests on memory leaks and other internal errors

This adds a new `--debug-exit-on-error` flag. When it is set, Blender
will abort with a non-zero exit code when there are internal errors.
Currently, "internal errors" includes memory leaks detected by
guardedalloc and error/fatal log entries in clog.

The new flag is passed to Blender in various places where automated
tests are run. Furthermore, the `--debug-memory` flag is used in tests,
because that makes the verbose output more useful, when dealing
with memory leaks.

Reviewers: brecht, sergey

Differential Revision: https://developer.blender.org/D8665

tests/python/modules/test_utils.py

@@ -79,6 +79,8 @@ class AbstractBlenderRunnerTest(unittest.TestCase):
             '-noaudio',
             '--factory-startup',
             '--enable-autoexec',
+            '--debug-memory',
+            '--debug-exit-on-error',
         ]
 
         if blendfile: