Older versions are not supported by the cmake module since 0.62.
This avoids having to hard-code the linux-bionic-gcc CI job as being
unable to run these tests, which leaves other older environments like
Debian 10 still trying to run them (and failing).
Signed-off-by: Simon McVittie <smcv@collabora.com>
Right now sub-sub projects are not correctly registered, because we
don't have a way to pass up past the first level of subproject. This
patch changes that by making the build_Def_files as defined in the
Interpreter initializer accurate for translated dependencies, ie, cmake
dependencies won't define a dependency on a non-existent meson.build.
This means that it can always add the subi.build_def_files because they
are always accurate.