Fix compat with Coq 8.15 & fix warnings.

theories/examples/folly_queue/refinement.v

theories/examples/folly_queue/set.v

theories/examples/stack/CG_stack.v

theories/examples/stack_helping/offers.v

theories/examples/symbol.v

theories/examples/various.v

theories/experimental/hocap/counter.v

theories/lib/lock.v

theories/logic/adequacy.v

theories/logic/model.v

theories/logic/spec_ra.v

theories/prelude/lang_facts.v

theories/typing/contextual_refinement.v

theories/typing/types.v