[clang] [LifetimeSafety] Introduce intra-procedural analysis in Clang (PR #142313)

[Baranov Victor via cfe-commits]

https://github.com/vbvictor commented:

Thank you for your work! Interested to see this feature in clang.
Left a couple of nit comments on code style.

https://github.com/llvm/llvm-project/pull/142313