[clang] [LifetimeSafety] Track origins through std::function (PR #191123)

[Gábor Horváth via cfe-commits]

https://github.com/Xazax-hun commented:

I have one major question inline, whether we want to have a new kind of fact or modify the existing flow fact. Otherwise, the overall direction looks good to me. 

https://github.com/llvm/llvm-project/pull/191123