Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix copyright comment & FBSDID style nits.

Requested by: bde

Use __FBSDID().

Introduce atomic_cmpset_int() and atomic_cmpset_long() from SMPng a
few hours earlier than the rest.

The next DEVFS commit needs these functions.

Alpha versions by: dfr
i386 versions by: jakeb

Approved by: SMPng

$Id$ -> $FreeBSD$

Cosmetic: Correct the Id string.

Submitted by: Peter Jeremy <jeremyp@gsmx07.alcatel.com.au>

Create callable (non-inline) versions of the atomic_OP_TYPE functions
that are linked into the kernel. The KLD compilation options are
changed to call these functions, rather than in-lining the
atomic operations.

This approach makes atomic operations from KLDs significantly
faster on UP systems (though somewhat slower on SMP systems).

PR: i386/13111
Submitted by: peter.jeremy@alcatel.com.au