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

[via cfe-commits]

yronglin wrote:

> 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.

Many thanks for the review!

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