Issue #28701: Replace PyUnicode_CompareWithASCIIString with _PyUnicode_EqualToASCIIString.

The latter function is more readable, faster and doesn't raise exceptions.

Modules/_pickle.c

@@ -1675,7 +1675,7 @@ whichmodule(PyObject *global, PyObject *dotted_path)
     while (PyDict_Next(modules_dict, &i, &module_name, &module)) {
         PyObject *candidate;
         if (PyUnicode_Check(module_name) &&
-            !PyUnicode_CompareWithASCIIString(module_name, "__main__"))
+            _PyUnicode_EqualToASCIIString(module_name, "__main__"))
             continue;
         if (module == Py_None)
             continue;