bpo-39573: Use Py_SET_SIZE() function (GH-18402)
Replace direct acccess to PyVarObject.ob_size with usage of
the Py_SET_SIZE() function.
diff --git a/Objects/stringlib/split.h b/Objects/stringlib/split.h
index 31f77a7..068047f 100644
--- a/Objects/stringlib/split.h
+++ b/Objects/stringlib/split.h
@@ -48,7 +48,7 @@
/* Always force the list to the expected size. */
-#define FIX_PREALLOC_SIZE(list) Py_SIZE(list) = count
+#define FIX_PREALLOC_SIZE(list) Py_SET_SIZE(list, count)
Py_LOCAL_INLINE(PyObject *)
STRINGLIB(split_whitespace)(PyObject* str_obj,