Summary:
On macOS, the compiler shows tons of warnings due to our use of pointers where
nullability attributes aren't set, and the compiler complains about it. This
makes finding legitimate warnings/errors almost impossible, thus for now let's
disable these.
Reviewed By: fanzeyi
Differential Revision: D27862116
fbshipit-source-id: 8ea2c27a0cfd6cbd484fca6be5f15c772d9f4589
