make sure all Instance/Argument have explicit visibility

Makefile.coq.local

coq-lint.sh

theories/lang/adequacy.v

theories/lang/heap.v

theories/lang/lang.v

theories/lang/lib/arc.v

theories/lang/lib/spawn.v

theories/lang/lifting.v

theories/lifetime/lifetime.v

theories/lifetime/lifetime_sig.v

theories/lifetime/meta.v

theories/lifetime/model/definitions.v

theories/lifetime/model/primitive.v

theories/typing/function.v

theories/typing/lft_contexts.v

theories/typing/lib/arc.v

theories/typing/lib/brandedvec.v

theories/typing/lib/ghostcell.v

theories/typing/lib/rc/rc.v

theories/typing/lib/refcell/refcell.v