FreeBSD_HEAD - Build #2979 - Fixed

FreeBSD_HEAD - Build #2979 - Fixed:

Build information: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD/2979/
Full change log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD/2979/changes
Full build log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD/2979/console

Change summaries:

285663 by markj:
Modify lockstat_nsecs() to just return unless lockstat probes are actually
enabled. The cost of a timecounter read can be quite significant, and the
problem became more apparent after r284297, since that change resulted in
a call to lockstat_nsecs() for each acquisition of an rwlock read lock.

PR:		201642
Reviewed by:	avg
Tested by:	Jason Unovitch
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D3073

285662 by benno:
Merge driver for PMC Sierra's range of SAS/SATA HBAs.

Submitted by:	Achim Leubner <Achim.Leubner_at_pmcs.com>
Reviewed by:	scottl

285661 by ed:
Undo r285656.

It turns out that the CDDL sources already introduce a function called
thread_create(). I'll investigate what we can do to make these functions
coexist.

Reported by: Ivan Klymenko