sys: Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Fix some modules to export more used symbols

and remove non-present symbols that are now reported by kmod_syms.awk.

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32878

modules: a lot: need opt_kern_tls.h

This fixes the standalone build.

Fix build in sys/modules/nfscommon

Sponsored by: The FreeBSD Foundation

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64
MFC after: 1 month
Sponsored by: Dell EMC Isilon

- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip

Fix make buildworld -DMODULES_WITH_WORLD
Sort opt_ srcs

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

Add the kernel build glue for the experimental NFS subsystem that
includes support for NFSv4. The subsystem can optionally be linked
into the kernel using the two options:
NFSCL - the client
NFSD - the server
It is also built as three modules:
nfscl - the client
nfsd - the server
nfscommon - functions shared by the client and server

Approved by: kib (mentor)