[clang] #101784 part 2: fix error handling of TranslationUnit.reparse (PR #102410)

[Jannick Kremer via cfe-commits]

https://github.com/DeinAlptraum commented:

A couple minor comments, and the code formatting should be fixed (see output of the failing CI run), and then this is good to go!

https://github.com/llvm/llvm-project/pull/102410