meson: prefix the names of the tests so that they are unique in the tree
meson < 0.46 does not allow two targets to share the same name; meson >= 0.46 relaxes that requirement, but I see no reason to require a new version of meson just for this
meson < 0.46 does not allow two targets to share the same name; meson >= 0.46 relaxes that requirement, but I see no reason to require a new version of meson just for this