Issue #6477: Added support for pickling the types of built-in singletons.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index d62f014..386ffba 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -728,9 +728,18 @@
 
         self.memoize(obj)
 
+    def save_type(self, obj):
+        if obj is type(None):
+            return self.save_reduce(type, (None,), obj=obj)
+        elif obj is type(NotImplemented):
+            return self.save_reduce(type, (NotImplemented,), obj=obj)
+        elif obj is type(...):
+            return self.save_reduce(type, (...,), obj=obj)
+        return self.save_global(obj)
+
     dispatch[FunctionType] = save_global
     dispatch[BuiltinFunctionType] = save_global
-    dispatch[type] = save_global
+    dispatch[type] = save_type
 
 # Pickling helpers