Move typing_extensions to stdlib (#5233)

I'm not sure what the best way to do this is. This effectively orphans
types-typing-extensions, but maybe that's not really a problem. (We can
yank the package too)

See https://github.com/python/typeshed/pull/5229#issuecomment-822234125
for some details

Co-authored-by: hauntsaninja <>

stdlib/VERSIONS

@@ -233,6 +233,7 @@ tty: 2.7
 turtle: 2.7
 types: 3.6
 typing: 3.6
+typing_extensions: 2.7
 unicodedata: 2.7
 unittest: 3.6
 urllib: 3.6