bpo-38525: Fix segfault when using reverse iterators of empty dict literals by pablogsal · Pull Request #16847 · python/cpython
This was a consequence of
commit f2a186712bfe726d54723eba37d80c7f0303a50b
Author: Inada Naoki <songofacandy@gmail.com>
Date: Tue Mar 12 17:25:44 2019 +0900
[bpo-30040](https://bugs.python.org/issue30040): new empty dict uses key-sharing dict (GH-1080)
Sizeof new empty dict becomes 72 bytes from 240 bytes (amd64).
It is same size to empty dict created by dict.clear().
and
commit 6531bf6309c8fda1954060a0fb5ea930b1efb656
Author: Rémi Lapeyre <remi.lapeyre@henki.fr>
Date: Tue Nov 6 01:38:54 2018 +0100
[bpo-33462](https://bugs.python.org/issue33462): Add __reversed__ to dict and dict views (GH-6827)
together.