Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

dtrace: improve siftr probe

Improve consistency of the field names with tcpsinfo_t:
* Use mss instead of max_seg_size.
* Use lport and rport instead of tcp_localport and tcp_foreignport.

Use t_flags instead of flags to improve consistency with t_flags2.

Add laddr and raddr, since the addresses were missing when compared
to the output of siftr.

Reviewed by: cc
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D40834

dtrace: third update to the siftr probe

This adds the changes corresponding to
https://cgit.freebsd.org/src/commit/?id=60167184abd54ca12c6bf7ab60f2a08b41342f84
to the siftr probe.
This concludes the series up updates.

Reviewed by: rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D40825

dtrace: another update of the siftr probe

This adds the changes corresponding to
https://cgit.freebsd.org/src/commit/?id=d090464ecd4af5cd400ef5cbbfe8409d019eac34
to the siftr probe.

Reviewed by: rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D40824

dtrace: update siftr probe

This adds the changes corresponding to
https://cgit.freebsd.org/src/commit/?id=1241e8e7aed5d709a6cf62024e9ae750981c03ae
to the siftr probe.

Reviewed by: rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D40823

dtrace: fix constants used by the siftr probe

The constants used in the C code were changed in
https://svnweb.freebsd.org/changeset/base/343646
but changing them also in the dtrace translator was missed.

Reviewed by: cc, rscheff
MFC after: 3 days
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D40805

- Use an explicit "depends_on module kernel" guard in DTrace libraries that
reference types defined in the kernel. Otherwise dtrace(1) expects to find
CTF definitions for all referenced types, which is not very reasonable
when it is being used in a build environment. This was previously worked
around by adding "-x nolibs" to dtrace -h or -G invocations, but as of
r283025, dtrace(1) actually handles dependencies properly, so this is no
longer necessary.
- Remove "pragma ident" directives from DTrace libraries, as they're being
phased out upstream as well.

Submitted by: Krister Johansen <Krister.Johansen@isilon.com> [1]
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Move siftr-related definitions out of tcp.d and into a separate library
which declares a dependency on siftr(4). This is necessitated by a
reference to struct pkt_node, which is defined in siftr(4): otherwise,
dtrace(1) will return an error during startup if siftr.ko is not loaded.