Added __instancecheck__ and __subclasscheck__ to type (#887)

stdlib/3/builtins.pyi

@@ -72,6 +72,8 @@ class type:
     # Note: the documentation doesnt specify what the return type is, the standard
     # implementation seems to be returning a list.
     def mro(self) -> List[type]: ...
+    def __instancecheck__(self, instance: Any) -> bool: ...
+    def __subclasscheck__(self, subclass: type) -> bool: ...
 
 class super(object):
     @overload