meson: actually #define HAVE_ASPRINTF

I believe this should now correctly enable the code iff it's needed.

This commits and the parent will probably be no-op in practice.
I believe distros commonly do use fortification by default,
and I'm not aware of any platform with kresd and without asprintf().

I considered using `conf_data.set()` in meson, but that would require
us modifying contrib/ccan/asprintf/asprintf.h to include kresconfig.h,
and that seemed weird.
25 jobs for asprintf-cleanup in 47 minutes and 14 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed #357472
amd64 linux docker
archive

00:01:04

passed #357473
amd64 linux docker
build

00:01:11

passed #357474
amd64 linux docker
build-asan

00:01:06

passed #357475
docker
kres-gen

00:01:06

 
  Test
passed #357476
docker delayed
build:darwin

00:01:27

passed #357477
amd64 linux docker
deckard

00:03:13

passed #357478
docker delayed
doc

00:01:20

passed #357479
dind
docker

00:01:53

passed #357480
docker delayed
lint:other

00:01:17

passed #357481
amd64 linux docker delayed
lint:pedantic

00:01:21

passed #357482
amd64 linux docker
lint:scan-build

00:03:03

passed #357483
amd64 linux docker
lint:tidy

00:03:51

passed #357484
amd64 linux docker
respdiff:basic

00:03:08

passed #357485
amd64 linux docker delayed
test:valgrind

00:02:28

 
  Extended
failed #357487
respdiff
fwd-tls6-kresd.udp6

00:21:51

passed #357488
respdiff
fwd-udp6-kresd.udp6

00:32:22

failed #357492
respdiff
fwd-udp6-unbound.tcp6

00:39:55

passed #357493
respdiff
fwd-udp6-unbound.tls6

00:40:25

passed #357491
respdiff
fwd-udp6-unbound.udp6

00:41:25

failed #357490
respdiff
iter.tls6

00:24:24

failed #357489
respdiff
iter.udp6

00:27:24

passed #357486
amd64 linux docker
pytests

00:04:01

passed #357494
respdiff
resperf:fwd-tls6.udp-asan

00:22:49

passed #357495
respdiff
resperf:fwd-udp6.udp-asan

00:19:49

passed #357496
respdiff
resperf:iter.udp-asan

00:20:19

 
Name Stage Failure
failed
fwd-udp6-unbound.tcp6 Extended
$ cp -t . respdiff_commitdir/*$RESPDIFF_TEST*.png ||:
$ cat respdiff_commitdir/$RESPDIFF_TEST/*histogram.tar.gz | tar -xf - -i ||:
Uploading artifacts...
Runtime platform arch=amd64 os=linux pid=158493 revision=003fe500 version=12.7.1
./j*: found 18 matching files

./*.png: found 2 matching files

./*histogram/*: found 5 matching files

Uploading artifacts to coordinator... ok
id=357492 responseStatus=201 Created token=H-eeF1Mr
ERROR: Job failed: exit status 1
failed
iter.udp6 Extended
$ cp -t . respdiff_commitdir/*$RESPDIFF_TEST*.png ||:
$ cat respdiff_commitdir/$RESPDIFF_TEST/*histogram.tar.gz | tar -xf - -i ||:
Uploading artifacts...
Runtime platform arch=amd64 os=linux pid=156700 revision=003fe500 version=12.7.1
./j*: found 18 matching files

./*.png: found 2 matching files

./*histogram/*: found 5 matching files

Uploading artifacts to coordinator... ok
id=357489 responseStatus=201 Created token=wv3PjRRz
ERROR: Job failed: exit status 1
failed
iter.tls6 Extended
$ cp -t . respdiff_commitdir/*$RESPDIFF_TEST*.png ||:
$ cat respdiff_commitdir/$RESPDIFF_TEST/*histogram.tar.gz | tar -xf - -i ||:
Uploading artifacts...
Runtime platform arch=amd64 os=linux pid=156243 revision=003fe500 version=12.7.1
./j*: found 18 matching files

./*.png: found 2 matching files

./*histogram/*: found 5 matching files

Uploading artifacts to coordinator... ok
id=357490 responseStatus=201 Created token=9ry7KTQ3
ERROR: Job failed: exit status 1
failed
fwd-tls6-kresd.udp6 Extended
$ cp -t . respdiff_commitdir/*$RESPDIFF_TEST*.png ||:
$ cat respdiff_commitdir/$RESPDIFF_TEST/*histogram.tar.gz | tar -xf - -i ||:
Uploading artifacts...
Runtime platform arch=amd64 os=linux pid=155714 revision=003fe500 version=12.7.1
./j*: found 17 matching files

./*.png: found 2 matching files

./*histogram/*: found 4 matching files

Uploading artifacts to coordinator... ok
id=357487 responseStatus=201 Created token=63UvNLJ5
ERROR: Job failed: exit status 1