bsd.own.mk: rename GCC_NO_* to CC_WNO_*

Rename compiler-warning-disable variables from
GCC_NO_warning
to
CC_WNO_warning
where warning is the full warning name as used by the compiler.

GCC_NO_IMPLICIT_FALLTHRU is CC_WNO_IMPLICIT_FALLTHROUGH

Using the convention CC_compilerflag, where compilerflag
is based on the full compiler flag name.

build lfs_node.c with -O3 on ia64 to avoid assembler overflow issues.

remove GCC_NO_ADDR_OF_PACKED_MEMBER for several subdir builds
that are now handled by lfs_accessors.h internally.

add support for new GCC 9 warnings that may be too much to fix
right now. new address-of-packed-member and format-overflow
warnings have new GCC_NO_ADDR_OF_PACKED_MEMBER amd
GCC_NO_FORMAT_OVERFLOW variables to remove these warnings.

apply to a bunch of the tree. mostly, these are real bugs that
should be fixed, but in many cases, only by removing the 'packed'
attribute from some structure that doesn't really need it. (i
looked at many different ones, and while perhaps 60-80% were
already properly aligned, it wasn't clear to me that the uses
were always coming from sane data vs network alignment, so it
doesn't seem safe to remove packed without careful research for
each affect struct.) clang already warned (and was not erroring)
for many of these cases, but gcc picked up dozens more.

introduce some common variables for use in GCC warning disables:

GCC_NO_FORMAT_TRUNCATION -Wno-format-truncation (GCC 7/8)
GCC_NO_STRINGOP_TRUNCATION -Wno-stringop-truncation (GCC 8)
GCC_NO_STRINGOP_OVERFLOW -Wno-stringop-overflow (GCC 8)
GCC_NO_CAST_FUNCTION_TYPE -Wno-cast-function-type (GCC 8)

use these to turn off warnings for most GCC-8 complaints. many
of these are false positives, most of the real bugs are already
commited, or are yet to come.


we plan to introduce versions of (some?) of these that use the
"-Wno-error=" form, which still displays the warnings but does
not make it an error, and all of the above will be re-considered
as either being "fix me" (warning still displayed) or "warning
is wrong."

branches: 1.16.28;
revert part of previous commit

fix compilation

branches: 1.14.2;
use getfsspecname()

branches: 1.13.2;
use a union to eliminate strict alias warnings.

apply some -Wno-error and/or -fno-strict-aliasing.


all of this should be looked at closer, but some of them are not
very trivial.

Enable WARNS=4 by default except for:
dump dump_lfs fsck_ffs fsck_lfs fsdb mount_smbfs
newfs_ext2fs newfs_lfs resize_lfs setkey

Comment out CFLAGS+=-g.

branches: 1.9.4; 1.9.6;
Enable gcc optimization on m68000 (sun2) again with minimum hacks.
gcc -O0 generates a bit fat binaries.

branches: 1.8.4; 1.8.6;
make all sun2 use -O0 and move most of the hacks out into just 3 files.

branches: 1.7.10; 1.7.12;
work around some GCC4 internal problems on m68000 platform.
document the hack, and update another GCC4 list.

Snapshot support for dump(8):

- New option `-x backup' takes the dump from a snapshot backed up by `backup'.
The snapshot will be deleted on exit.

- New option `-X' as a synonym for `-x mountpoint' where `mountpoint' is the
file system to be dumped.

Reviewed and Approved by: Manuel Bouyer <bouyer@netbsd.org>

branches: 1.5.6;
Remove "setgid tty" and references to utmp code from usr.bin/who.

Use ${NETBSDSRCDIR}/some/path instead of ${.CURDIR}/../../some/path

Fix dump_lfs build following recent utmp changes.

Merge the short-lived perseant-lfsv2 branch into the trunk.

Kernels and tools understand both v1 and v2 filesystems; newfs_lfs
generates v2 by default. Changes for the v2 layout include:

- Segments of non-PO2 size and arbitrary block offset, so these can be
matched to convenient physical characteristics of the partition (e.g.,
stripe or track size and offset).

- Address by fragment instead of by disk sector, paving the way for
non-512-byte-sector devices. In theory fragments can be as large
as you like, though in reality they must be smaller than MAXBSIZE in size.

- Use serial number and filesystem identifier to ensure that roll-forward
doesn't get old data and think it's new. Roll-forward is enabled for
v2 filesystems, though not for v1 filesystems by default.

- The inode free list is now a tailq, paving the way for undelete (undelete
is not yet implemented, but can be without further non-backwards-compatible
changes to disk structures).

- Inode atime information is kept in the Ifile, instead of on the inode;
that is, the inode is never written *just* because atime was changed.
Because of this the inodes remain near the file data on the disk, rather
than wandering all over as the disk is read repeatedly. This speeds up
repeated reads by a small but noticeable amount.

Other changes of note include:

- The ifile written by newfs_lfs can now be of arbitrary length, it is no
longer restricted to a single indirect block.

- Fixed an old bug where ctime was changed every time a vnode was created.
I need to look more closely to make sure that the times are only updated
during write(2) and friends, not after-the-fact during a segment write,
and certainly not by the cleaner.

branches: 1.1.4; 1.1.10;
Adapt dump(8) to use filestore-independent (but still ufs-specific)
replacements for NINDIR, fsbtodb, etc. Create dump_lfs by adding a few
LFS-filestore-specific routines. As described in PR#8317.