[clang] [LifetimeSafety] Add multi-block support to buildOriginFlowChain (PR #204592)

[via cfe-commits]

https://github.com/NeKon69 commented:

This looks pretty good to me! Though I am wondering whether we actually need all this debug stuff in `buildOriginFlowChain`.

https://github.com/llvm/llvm-project/pull/204592