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

[via cfe-commits]

https://github.com/NeKon69 commented:

I did not do a deep review of this yet since this is pretty complex but here's what I got from just a quick scan.

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