f7984cfbee
This is one of the few post gcc4.2 builtins that has been implemented by clang: __builtin_unreachable is used to indicate that a specific point in the program cannot be reached, even if the compiler might otherwise think it can. This is useful to improve optimization and eliminates certain warnings. Hinted by: NetBSD Differential Revision: https://reviews.freebsd.org/D2536