Closes #22205: sys._debugmallocstats is a cpython specific feature, so
test_debugmallocstats should be marked as such. Patch written by Martin
Matusiak.
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index a68ed08..93960cd 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -657,6 +657,7 @@
         self.assertEqual(sys.implementation.name,
                          sys.implementation.name.lower())
 
+    @test.support.cpython_only
     def test_debugmallocstats(self):
         # Test sys._debugmallocstats()
         from test.script_helper import assert_python_ok