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.

usr.bin/config: Suppress -Werror=stringop-truncation error.

Add GCC_NO_STRINGOP_TRUNCATION to scan.c to prevent build failure.

Error was reported when build.sh was run with MKLIBCSANITIZER=yes flag.
gcc version 8.3.0

Reviewed by: kamil@

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: 1.10.16;
put back scanner warnings now that flex produces clean code.

- add RCSID's
- fix -Wconversion (except scanner)

branches: 1.8.54;
Using ${NETBSDSRCDIR} requires <bsd.own.mk>

Enable the code that adds global constants to every kernel object file
that uses each configuration parameter.
This will stop kernel objects build with different options (that come from
config files) being linked together or loaded as a LKM.
Currently some options that have an effect on the kernel DDI/KI are passed
directly as parameters to cc.
An aim (for anyone adequately bored) would be to reduce the number of these
constants that appear in each .o file. .o files with the same constants
should be sharable between kernels (even between XEN and i386).

Introduce a new option to config(1): -L. What it does is takes a regular
configuration file (although it is meant to be used mostly with
std.${ARCH}), and prints out a configuration file that includes it and
select every single option and parameter, and define an instance for every
single possible attachment. IOW, selects everything, into a would-be
"LINT" config.

The resulting config really isn't meant to be runnable, but should be
somewhat buildable on most archs. It still needs adjustments because some
options are peculiar (e.g., ACPI_DSDT_FILE wants an existing file as its
value), so it's not yet possible to do "config -L; config; build" in an
automated way.

protect libutil with HOSTPROG

Now that this is part of tools, we don't need the extra build glue.

Install config.5 and config.samples.5.

branches: 1.2.2;
Remove bogus BINDIR assignment.

config and genassym are not sysadmin tools, they are development tools.
As such, they don't belong in /usr/sbin, but rather /usr/bin. Move them
there.