Currently, if the libmount feature is disabled, we don't build
libshared and as a result skip building every other executable as
well. Among other things, this makes our nodeps CI builds kind of
pointless since hardly any code will be compiled.
Let's improve on the situation by making libmount properly optional
in libshared. Then, we only skip building the executables that
actually need libmount.
Now our baseline of meson is 0.62, hence install_symlink() can be used.
Note, install_symlink() implies install_emptydir() for specified
install_dir. Hence, this also drops several unnecessary
install_emptydir() calls.
Note, the function currently does not support 'relative' and 'force' flags,
so several 'ln -frsT' inline calls cannot be replaced.
This was requested, though I think an issue was never filed. If people are
supposed to invoke it, even for testing, then it's reasonable to make it
"public".
Daan De Meyer
Lennart Poettering
Mike Yuan
Yu Watanabe
Gabríel Arthúr Pétursson
Zbigniew Jędrzejewski-Szmek
Jan Janssen
Peter Cai