regrtest: don't fail immediately if a child does crash

Issue #29362: Catch a crash of a worker process as a normal failure and
continue to run next tests. It allows to get the usual test summary: single
line result (OK/FAIL), total duration, etc.
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index 61a9876..de1f4f9 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -107,7 +107,7 @@
             self.test_times.append((test_time, test))
         if ok == PASSED:
             self.good.append(test)
-        elif ok == FAILED:
+        elif ok in (FAILED, CHILD_ERROR):
             self.bad.append(test)
         elif ok == ENV_CHANGED:
             self.environment_changed.append(test)