[clang] [LifetimeSafety] Add ExpireOriginFact to fix false positives for pointers in loops (PR #182368)

[Utkarsh Saxena via cfe-commits]

usx95 wrote:

IIUC, it would always have a LoanID. The OriginID would be optional depending on the expiring entity has an associated origin or not.

This would become simpler when we move from expiring loans to expiring paths (storages)

https://github.com/llvm/llvm-project/pull/182368