[clang] [clang] Merge lifetimebound and GSL code paths for lifetime analysis (PR #104906)

[Louis Dionne via cfe-commits]

ldionne wrote:

@hokein @vvereschaka Yeah, I get the same conclusion as you. I think that's a false positive, this is just moving the content of an engaged `std::optional`.

https://github.com/llvm/llvm-project/pull/104906