Minimal changes to make the "freeze" tool work again.
There are other issues left, but these were basics (e.g. keys().sort()).
diff --git a/Tools/freeze/bkfile.py b/Tools/freeze/bkfile.py
index c67a6c4..0e895f2 100644
--- a/Tools/freeze/bkfile.py
+++ b/Tools/freeze/bkfile.py
@@ -21,7 +21,10 @@
         self.mode = self.__file.mode
         self.name = self.__file.name
         self.read = self.__file.read
-        self.readinto = self.__file.readinto
+        try:
+            self.readinto = self.__file.readinto
+        except AttributeError:
+            pass
         self.readline = self.__file.readline
         self.readlines = self.__file.readlines
         self.seek = self.__file.seek