offline-passwd.[ch] are only used by systemd-tmpfiles and the relevant
test. And are not included in libshared. So, it is not suitable to
located under src/shared.
The test binary has two modes: in the default argument-less mode, it
just checks that "root" can be resolved. When invoked manually, a root
prefix and user/group names can be specified.
Use -Dstandalone-binaries=yes to enable building and installing this standalone
version of the binary without a dependency on the systemd-shared solib.
Also move the list of sources for systemd-tmpfiles to its own meson.build file.
Yu Watanabe
Zbigniew Jędrzejewski-Szmek
Filipe Brandenburger