MC: Extract the task queue type from the final machine stack.

divine/mc/machine.hpp

@@ -491,9 +491,19 @@ namespace divine::mc
     struct TMachine : machine::tree< smt::NoSolver > {};
     struct GMachine : machine::graph< smt::NoSolver > {};
 
+    template< typename M >
+    struct TQ : M::tq {};
+
+    template< typename M >
+    struct MW
+    {
+        struct TQ : M::tq {};
+        struct W : Weaver< TQ > {};
+    };
+
     template< typename M >
     auto weave( M &machine )
     {
-        return mc::Weaver< typename M::tq >().extend_ref( machine );
+        return typename MW< M >::W().extend_ref( machine );
     }
 }