[clang] [LifetimeSafety] Associate origins to all l-valued expressions (PR #156896)

[Utkarsh Saxena via cfe-commits]

usx95 wrote:

Since we discussed this patch briefly f2f and no major concerns were raised, I will land this for now @ymand . Happy to address review comments post commit.

https://github.com/llvm/llvm-project/pull/156896