[clang] [clang][bytecode] Support compile-time exceptions (PR #189410)

[Timm Baeder via cfe-commits]

tbaederr wrote:

I have removed the support for `__builtin_uncaught_exceptions()` and `__builtin_current_exceptions` again for now since they also require a codegen side and I'm not sure how that would work.

https://github.com/llvm/llvm-project/pull/189410