[test] Add basic _Unwind_ForcedUnwind + exception tests

Forced unwinding is like a foreign exception, which can be caught by `catch (...)` and rethrown.
If not rethrown, `__cxa_end_cath` will call `_Unwind_DeleteException` to destroy the object.

The behavior going through empty `throw()` and non-empty `throw(int)` is not
clear (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98785), so I do not add such

Differential Revision: https://reviews.llvm.org/D95200

GitOrigin-RevId: 81af8149d8cb8ff65f2569d813252fab2a14df00
2 files changed