[clang] [LifetimeSafety] Fix crash on ternary operator when one of the expressions is `throw` (PR #190345)

[Gábor Horváth via cfe-commits]

Xazax-hun wrote:

Since we do full dataflow analysis on the generated facts, I think we do not need to be that precise while we generate the facts after all. So I think the simple/cheap solution should be fine. 

https://github.com/llvm/llvm-project/pull/190345