[clang] [LifetimeSafety] Introduce buildOriginFlowChain to use-after-invalidation (PR #208891)

[Yuan Suo via cfe-commits]

suoyuan666 wrote:

Thanks! Could someone help merge this? I don't have merge permissions yet.

I just rebased locally and reran `cmake --build build -t check-clang-sema`, and everything passed. I don't think merging it in the near term should cause any issues.

https://github.com/llvm/llvm-project/pull/208891