[clang] [LifetimeSafety] Track origins for lifetimebound calls returning record types (PR #187917)

[Zhijie Wang via cfe-commits]

aeft wrote:

@usx95 

About documentation, since we already have a doc for the Lifetime Safety Analysis, should I update it to reflect this feature? If so, can I do this in a separate PR since this one is already quite large?

Also, what's the preferred practice for maintaining the docs? Should they be updated alongside each PR, or periodically?

https://github.com/llvm/llvm-project/pull/187917