[clang] Reapply "[Analyzer][CFG] Correctly handle rebuilt default arg and default init expression" (PR #127338)

[Balazs Benics via cfe-commits]

https://github.com/steakhal approved this pull request.

Well, I don't really know much about these default init exprs but your explanation looks reasonable. I'd say, we should try it and revert it again if there are still some problems.

https://github.com/llvm/llvm-project/pull/127338