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

[Jan Voung via cfe-commits]

jvoung wrote:

In case others notice similar in ClangTidy (`bugprone-unchecked-optional-access`), we are seeing crashes after this change https://github.com/llvm/llvm-project/issues/128068

I'm not yet sure the best fix.

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