Sync to typeshed branch release-0.590 which has python#2039 cherry-picked in it

Guido van Rossum · Guido van Rossum · commit 76ceedc14a0a · 2018-04-11T07:39:18.000-07:00
diff --git a/typeshed b/typeshed
@@ -1 +1 @@
-Subproject commit 81a6ea43a580c68a6a78154a10258dd0b98ebbd3
+Subproject commit b115ebca392a470346b06684ede6a5f92a54e701
