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/render_report.py

@@ -448,16 +448,17 @@ class Report:
             crash = False
             output = None
             try:
-                output = subprocess.check_output(command)
-            except subprocess.CalledProcessError as e:
-                crash = True
+                completed_process = subprocess.run(command, stdout=subprocess.PIPE)
+                if completed_process.returncode != 0:
+                    crash = True
+                output = completed_process.stdout
             except BaseException as e:
                 crash = True
 
             if verbose:
                 print(" ".join(command))
-                if output:
-                    print(output.decode("utf-8"))
+            if (verbose or crash) and output:
+                print(output.decode("utf-8"))
 
             # Detect missing filepaths and consider those errors
             for filepath, output_filepath in zip(remaining_filepaths[:], output_filepaths):