[clang] [LifetimeSafety] Introduce buildOriginFlowChain for use-after-scope (PR #199345)

[Utkarsh Saxena via cfe-commits]

https://github.com/usx95 commented:

This has started to look really nice. Thanks. One larger suggestion to do the filtering in a separate function (like `shouldShowInAliasChain`)

https://github.com/llvm/llvm-project/pull/199345