bc2a8ef6f5
This is a follow-up to https://github.com/swiftlang/llvm-project/pull/12317#discussion_r2850297229 Per that discussion, given that deserializers *can* fail given a corrupt PDB, it's preferable to handle the error instead of crashing. This specific change is limited to "easy" changes (read: I have high confidence in their correctness). The ideal end state is funneling all errors to a few central places in `SymbolFileNativePDB`.