Revert CC_WNO_USE_AFTER_FREE from Makefile's (thanks uwe@)

Sprinkle CC_WNO_USE_AFTER_FREE for GCC 12

All of them are blamed for idiom equivalent to:
newbuf = realloc(buf, size);
p = newbuf + (p - buf);

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.

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: 1.8.46;
Save length of key instead of relying of the weight of the record sep.
This frees a byte value to use for 'end of key' (to correctly sort
short keys) while still having a weight assigned to the field sep.
(Unless -t is given, the field sep is in the field data.)
Do reverse sorts by writing the output file in reverse order (rather
than reversing the sort - apart from merges).
All key compares are now unweighted.
For 'sort -u' mark duplicates keys during the sort and don't write
to the output.
Use -S to mean a posix sort - where equal keys are sorted using the
raw record (rather than being kept in the original order).
For 'sort -f' (no keys) generate a key of the folded data (as for -n
-i and -d), simplifies the code and allows a 'posix' sort.

Include a local copy of the sradixsort() code from libc.
Currently unchanged apart from the deletion of the 'unstable' version and
other unneeded code.
Use fldtab[0]. not fldtab-> when we are referring to the global info
in the 0th entry to emphasise that this entry is different.
fldtab[0].weights is only needed in the SINGL_FLD case - so set it there.
Re-indent a big 'if' is setfield() so that the line breaks match the
logic - which looks dubious now!

Enable WARNS=4 by default for usr.bin, except for:
awk bdes checknr compile_et error gss hxtool kgetcred kinit
klist ldd less lex locale login m4 man menuc mk_cmds
mklocale msgc openssl rpcgen rpcinfo sdiff spell ssh
string2key telnet tn3270 verify_krb5_conf xlint

branches: 1.5.40; 1.5.42; 1.5.46;
this builds with WARNS=2

put tmp.c back to Makefile, too

make ftmp() wrapper aroung tmpfile(), there is no need to reimplement it
move ftmp() from tmp.c to files.c
g/c no longer needed stuff

Hit sort(1) with a hammer till it compiles.
Also add RCSIDs.

branches: 1.1.1;
Initial revision