[clang] [WIP][Safe Buffers] Serialize unsafe_buffer_usage pragmas (PR #92031)

[Artem Dergachev via cfe-commits]

https://github.com/haoNoQ commented:

I'm very happy that this is going somewhere! Everything makes sense to me but I also don't know a lot about this stuff.

> During serialization, it only serializes regions of the current translation unit. Regions from loaded files are not serialized.

Hmm how does this work? When a precompiled header includes another precompiled header, do they both get loaded independently and then you get to combine the maps?

https://github.com/llvm/llvm-project/pull/92031