Issue #14785: Add sys._debugmallocstats() to help debug low-level memory allocation issues

Objects/listobject.c

@@ -117,6 +117,15 @@ PyList_Fini(void)
     PyList_ClearFreeList();
 }
 
+/* Print summary info about the state of the optimized allocator */
+void
+_PyList_DebugMallocStats(FILE *out)
+{
+    _PyDebugAllocatorStats(out,
+                           "free PyListObject",
+                           numfree, sizeof(PyListObject));
+}
+
 PyObject *
 PyList_New(Py_ssize_t size)
 {