regrtest: dump all threads on a crash, not only the current thread
diff --git a/Lib/test/regrtest.py b/Lib/test/regrtest.py
index 0b7e3d2..120bd60 100755
--- a/Lib/test/regrtest.py
+++ b/Lib/test/regrtest.py
@@ -1589,7 +1589,7 @@
 
 if __name__ == '__main__':
     # Display the Python traceback on segfault and division by zero
-    faulthandler.enable()
+    faulthandler.enable(all_threads=True)
 
     # Remove regrtest.py's own directory from the module search path. Despite
     # the elimination of implicit relative imports, this is still needed to