Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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