FreeBSD/src 9f360ee (r340415)sys/kern subr_epoch.c, sys/sys epoch.h

The dualism between epoch_tracker and epoch_thread is fragile and
unnecessary. So, expose CK types to kernel and use a single normal
structure for epoch_tracker.

Reviewed by:    jtl, gallatin
DeltaFile
+19-34sys/kern/subr_epoch.c
+16-16sys/sys/epoch.h
+35-502 files

UnifiedSplitRaw