Bug#716746: backport clock_getcpuclockid2 syscall into kfreebsd-9

[Petr Salinger <Petr.Salinger@seznam.cz>]

Package: kfreebsd-9
Severity: wishlist
User: debian-bsd@lists.debian.org
Usertags: kfreebsd

To properly provide CLOCK_THREAD_CPUTIME_ID, CLOCK_PROCESS_CPUTIME_ID
and clock_id's created by clock_getcpuclockid() and 
pthread_getcpuclockid(), we need a kernel support.
See also #665287.

The kernel support is available in HEAD (but not in STABLE-9).
It should not be to hard to backport kernel part of

http://www.freebsd.org/cgi/query-pr.cgi?pr=168417

into our kernel.

The FBTL based libpthread will use only this interface,
it will not fallback to TSC timers at all.
The reason is that TSC part is fragile and unaccurate.

Petr