Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

libsysdecode: Include required headers in sysdecode.h

Make sysdecode.h self-contained rather than forcing all consumers to
include dependencies. No functional change intended.

Reviewed by: pauamma_gundo.com, jhb, emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34899

Drop "All rights reserved" from my copyright statements.

Reviewed by: rgrimes
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D19485

Move mksubr from kdump into libsysdecode.

Restructure this script so that it generates a header of tables instead
of a source file. The tables are included in a flags.c source file which
provides functions to decode various system call arguments.

For functions that decode an enumeration, the function returns a pointer
to a string for known values and NULL for unknown values.

For functions that do more complex decoding (typically of a bitmask), the
function accepts a pointer to a FILE object (open_memstream() can be used
as a string builder) to which decoded values are written. If the
function operates on a bitmask, the function returns true if any bits
were decoded or false if the entire value was valid. Additionally, the
third argument accepts a pointer to a value to which any undecoded bits
are stored. This pointer can be NULL if the caller doesn't care about
remaining bits.

Convert kdump over to using decoder functions from libsysdecode instead of
mksubr. truss also uses decoders from libsysdecode instead of private
lookup tables, though lookup tables for objects not decoded by kdump remain
in truss for now. Eventually most of these tables should move into
libsysdecode as the automated table generation approach from mksubr is
less stale than the static tables in truss.

Some changes have been made to truss and kdump output:
- The flags passed to open() are now properly decoded in that one of
O_RDONLY, O_RDWR, O_WRONLY, or O_EXEC is always included in a decoded
mask.
- Optional arguments to open(), openat(), and fcntl() are only printed
in kdump if they exist (e.g. the mode is only printed for open() if
O_CREAT is set in the flags).
- Print argument to F_GETLK/SETLK/SETLKW in kdump as a pointer, not int.
- Include all procctl() commands.
- Correctly decode pipe2() flags in truss by not assuming full
open()-like flags with O_RDONLY, etc.
- Decode file flags passed to *chflags() as file flags (UF_* and SF_*)
rather than as a file mode.
- Fix decoding of quotactl() commands by splitting out the two command
components instead of assuming the raw command value matches the
primary command component.

In addition, truss and kdump now build without triggering any warnings.
All of the sysdecode manpages now include the required headers in the
synopsis.

Reviewed by: kib (several older versions), wblock (manpages)
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D7847

errno(3) -> errno(2)

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Add handling for non-native error values to libsysdecode.

Add two new functions, sysdecode_abi_to_freebsd_errno() and
sysdecode_freebsd_to_abi_errno(), which convert errno values between
the native FreeBSD ABI and other supported ABIs. Note that the
mappings are not necessarily perfect meaning in some cases multiple
errors in one ABI might map to a single error in another ABI. In that
case, the reverse mapping will return one of the errors that maps, but
which error is non-deterministic.

Change truss to always report the raw error value to the user but
use libsysdecode to map it to a native errno value that can be used
with strerror() to generate a description. Previously truss reported
the "converted" error value. Now the user will always see the exact
error value that the application sees.

Change kdump to report the truly raw error value to the user. Previously
kdump would report the absolute value of the raw error value (so for
Linux binaries it didn't output the FreeBSD error value, but the positive
value of the Linux error). Now it reports the real (i.e. negative) error
value for Linux binaries. Also, use libsysdecode to convert the native
FreeBSD error reported in the ktrace record to the raw error used by the
ABI. This means that the Linux ABI can now be handled directly in
ktrsysret() and removes the need for linux_ktrsysret().

Reviewed by: bdrewery, kib
Helpful notes: wblock (manpage)
Differential Revision: https://reviews.freebsd.org/D5314