[clang] Fix crash on defaulted comparison recovery in Sema and AST (PR #210668)

[Mariya Podchishchaeva via cfe-commits]

https://github.com/Fznamznon requested changes to this pull request.

Hi, thank you for contribution but currently the patch is unreviewable because it seems it applies formatting changes to the whole Decl.cpp file. Please limit the patch only to the changes related to the bug being fixed and avoid applying any formatting changes outside this area.

https://github.com/llvm/llvm-project/pull/210668