lib: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

Remove $FreeBSD$: one-line .c pattern

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

libc: Check for readdir(2) errors in fts(3)

Previously, such errors were not distinguished from the end-of-directory
condition.

With improvements from Mahmoud Abumandour <ma.mandourr@gmail.com>.

Reviewed by: markj
PR: 262038
MFC after: 2 weeks

DTF_REWIND does nothing (since r247236) so retire its use

Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D19663

Clean up the vcs ID strings in libc's gen/ directory.

- Move CSRG IDs into __SCCSID().
- When a file has been copied, consistently use 'From: <tag>' for strings
referencing the version of the source file copied from in the license
block comment.
- Some of the 'From:' tags were using $FreeBSD$ that was being expanded on
each checkout. Fix those to hardcode the FreeBSD tag from the file that
was copied at the time of the copy.
- When multiple strings are present list them in "chronological" order,
so CSRG (__SCCSID) before FreeBSD (__FBSDID). If a file came from
OtherBSD and contains a CSRG ID from the OtherBSD file, use the order
CSRG -> OtherBSD -> FreeBSD.

Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D15831

fts_open: move bogus initialization further below, before it is used.

Move an unneeded initialization, introduced in r54770 to quiet down GCC,
to a place nearer to its first use. This has no practical effect, it just
keeps the garbage better sorted.

Hinted by: OpenBSD (CVS rev. 1.56, without obfuscations)

Commit the 64-bit inode project.

Extend the ino_t, dev_t, nlink_t types to 64-bit ints. Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment. Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks. Unfortunately, not everything can be
fixed, especially outside the base system. For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING. Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb). Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver. Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem). Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by: The FreeBSD Foundation (emaste, kib)
Differential revision: https://reviews.freebsd.org/D10439