Reduces numbers of files built for clang-format from 575 to 449.
Requires two small changes.
- Don't use llvm::ExceptionHandling in LangOptions. This isn't even quite the right type since we don't use all of its values. Tweaks the changes made in:
- Move section name validation code added (long ago) in commit 30ba67439 out of libBasic into Sema and base the check on the triple. This is a bit less OOP-y, but completely in line with what we do in many other places in Sema.
No behavior change.