typedef bool. Due to macro expansion it seemed better to use a
typedef for kernel consumers (specifically ofed won't compile
without more changes if a define is used).
- <stdbool.h> should also not re-define bool/true/false if they are
defined by <sys/types.h>. It would probably be a programming error
to define _KERNEL for user-space code, but downstream consumers
like Isilon have already been including <stdbool.h> in kernel
sources, and this protects that usage.
- sizeof(_Bool) is not necessarily the same as sizeof(int), so kernel
modules should be rebuild with this change. Bump __FreeBSD_version.
MFC after: 2 weeks
Sponsored by: Isilon Systems, LLC
