Function varisat::clause::gc::collect_garbage_now

fn collect_garbage_now(
    ctx: Const<TrailP, Mut<WatchlistsP, Mut<ImplGraphP, Mut<ClauseDbP, Mut<ClauseAllocP, Ref<Context>>>>>>
)

Unconditionally perform a garbage collection of long clauses.

This needs to invalidate or update any other data structure containing references to clauses.