Compiling the generated source for each consumer of the dependency
means we end up trying to register the enum types multiple times,
resulting in a fatal failure on startup. Luckily code outside libst
itself only depends on the header, which doesn't cause those issues.
st_built_sources contains the source and header generated by mkenums,
not any other generated sources. Clarify that in the name, as we are
about to use source and header separately.
We cannot rely on any build order, except the one we specify ourselves.
St depends on various generated files; other targets depend on those
files existing, so they can be included. There is no direct relationship
between targets and files, unless we declare a dependency, using the
Meson declare_dependency() constructor — which allows us to replace the
various `link_with` directives with the more appropriate `dependencies`
one, and also allows us to specify sources that must exist by the time
we build those targets.
Meson is on track to replace autotools as the build system of choice,
so support it in addition to autotools. If all goes well, we'll
eventually be able to drop the latter ...
https://bugzilla.gnome.org/show_bug.cgi?id=783229
