[clang] [WIP] [Modules] Delay reading type source info of the preferred_name attribute. (PR #122250)

[Ilya Biryukov via cfe-commits]

https://github.com/ilya-biryukov requested changes to this pull request.

Thanks for working on this!

After looking at the code, I think we should explore an alternative approach that would entail less duplication of serialization logic to ensure the code is correct for arbitrary TypeLocs and is more robust to changes.

See the relevant comment in ASTReaderDecl.cpp for more details.
I left a few more minor comments, but we could address them later (and they might get stale if we pick a different approach)

https://github.com/llvm/llvm-project/pull/122250