sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)

r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.

This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.

Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT

Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718

Extract eventfilter declarations to sys/_eventfilter.h

This allows replacing "sys/eventfilter.h" includes with "sys/_eventfilter.h"
in other header files (e.g., sys/{bus,conf,cpu}.h) and reduces header
pollution substantially.

EVENTHANDLER_DECLARE and EVENTHANDLER_LIST_DECLAREs were moved out of .c
files into appropriate headers (e.g., sys/proc.h, powernv/opal.h).

As a side effect of reduced header pollution, many .c files and headers no
longer contain needed definitions. The remainder of the patch addresses
adding appropriate includes to fix those files.

LOCK_DEBUG and LOCK_FILE_LINE_ARG are moved to sys/_lock.h, as required by
sys/mutex.h since r326106 (but silently protected by header pollution prior
to this change).

No functional change (intended). Of course, any out of tree modules that
relied on header pollution for sys/eventhandler.h, sys/lock.h, or
sys/mutex.h inclusion need to be fixed. __FreeBSD_version has been bumped.

spdx: initial adoption of licensing ID tags.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes: yes
Differential Revision: https://reviews.freebsd.org/D13133

Use intr_disable() and intr_restore() instead of frobbing the flags register
directly to disable interrupts.

Reviewed by: bde (earlier version)
MFC after: 2 weeks

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Introduce cpu_vendor_id and replace a lot of strcmp(cpu_vendor, "...").

Reviewed by: jhb, peter (early amd64 version)

- Import the HEAD csup code which is the basis for the cvsmode work.

Move the author's copyright notice to match the initial LongRun import
now that we have split out this support into longrun.c

Compiled longrun.c when defined options CPU_ENABLE_LONGRUN,
and fixed wrong comparation in cpu vendor. Longrun function
was re-enabled.

Move LongRun support out of identcpu.c, where it hardly belongs, into its
own file and make it opt-in, not mandatory, depending on CPU_ENABLE_LONGRUN
config(8) option.

Discussed with: nate
MFC after: 2 weeks