These wrap RELOADING=1 and STOPPING=1 messages. The former is
particularly useful, since we want to insert the MONOTONIC_USEC= field
into the message automatically, which is easy from C but harder from
shell.
We are basically already there, just need to add MONOTONIC_USEC= to the
RELOADING=1 message, and make sure the message is generated in really
all cases.
And send READY=1 again when we are done with it.
We do this not only for "daemon-reload" but also for "daemon-reexec" and
"switch-root", since from the perspective of an encapsulating service
manager these three operations are not that different.
We converted to not using #ifdef for most of our defines because the syntax is
nicer and we are protected against typos and can set -Werror=undef. Let's do
the same for SD_BOOT. The define is nicely hidden in build.h for normal builds,
and for EFI builds we were already setting SD_BOOT on the commandline.
Our HAVE_* variables are defined to 0 or 1, so '#if defined(HAVE_*)' is always true.
The variable is not defined when compiling for EFI though, so we need the
additional guard.
Fixup for 3f92dc2fd4.
(I don't want to do something like add -DHAVE_EXPLICIT_BZERO=0 to the commandline
in src/efi/boot/meson.build, because this quite verbose. Our compilation commandlines
are very long already. Let's instead keep this localized in this one spot in the
source file.)x
