[clang] [LifetimeSafety] Overhaul CFG and analysis to also work with trivially destructed temporary objects (PR #177985)

[Abhinav Pradeep via cfe-commits]

AbhinavPradeep wrote:

The changes switch now treat `CFGFullExprCleanup` as a liftime marker. 

This required reverting all the CFG-matcher test modifications I made, as those were testing dtors. There are two tests `clang/test/Analysis/lifetime-cfg-output.cpp` and `clang/test/Analysis/nonreturn-destructors-cfg-output.cpp` that toggle and test the liftime markers, but we seem to pass those without any modifications. 

I do plan to add additional tests with the next commit, just wanted some feedback prior to that!

https://github.com/llvm/llvm-project/pull/177985