Summary:
Modernize our null annotations
From the swift blog:
This feature was first released in Xcode 6.3 with the keywords nullable and nonnull. Due to potential conflicts with third-party libraries, we’ve changed them in Xcode 7 to the _Nullable and _Nonnull you see here.
drop-conflicts
Reviewed By: cuva
Differential Revision: D33121042
fbshipit-source-id: 821f5ec858d9afd5bfb1d6081c669f4ca18a36ed