This gives clang-format the right notion about formatting these struct
initializers, therefore allowing us to automatically format several
additional files.
# skip-blame because this is just a content-free comment addition
Differential Revision: https://phab.mercurial-scm.org/D1169
We mostly abide by this style.
In one case, a blank line was inserted to prevent a local
`#include "file"` from coming before a `#include <file>`.
Differential Revision: https://phab.mercurial-scm.org/D908
