Fix warnings about "unused" parameters and typedefs.

CLang and recent GCC warn about the "typedef" 'OneColInt' in
AutoDiffHelpers.hpp being unused.  Similarly, GCC warns about unused
parameters in various place at level "-Wunused".  This change-set
either removes ('OneColInt') or suppresses those messages.

opm/autodiff/AutoDiffHelpers.hpp

@@ -62,7 +62,6 @@ struct HelperOps
         const int nc = grid.number_of_cells;
         const int nf = grid.number_of_faces;
         // Define some neighbourhood-derived helper arrays.
-        typedef Eigen::Array<int, Eigen::Dynamic, 1> OneColInt;
         typedef Eigen::Array<bool, Eigen::Dynamic, 1> OneColBool;
         typedef Eigen::Array<int, Eigen::Dynamic, 2, Eigen::RowMajor> TwoColInt;
         typedef Eigen::Array<bool, Eigen::Dynamic, 2, Eigen::RowMajor> TwoColBool;

opm/autodiff/BlackoilPropsAd.cpp

@@ -456,6 +456,10 @@ namespace Opm
     V BlackoilPropsAd::rsMax(const V& po,
                              const Cells& cells) const
     {
+        // Suppress warning about "unused parameters".
+        static_cast<void>(po);
+        static_cast<void>(cells);
+
         OPM_THROW(std::runtime_error, "Method rsMax() not implemented.");
     }
 
@@ -466,6 +470,10 @@ namespace Opm
     ADB BlackoilPropsAd::rsMax(const ADB& po,
                                const Cells& cells) const
     {
+        // Suppress warning about "unused parameters".
+        static_cast<void>(po);
+        static_cast<void>(cells);
+
         OPM_THROW(std::runtime_error, "Method rsMax() not implemented.");
     }
 

opm/autodiff/ImpesTPFAAD.cpp

@@ -226,6 +226,10 @@ namespace {
                                      const BlackoilState& state,
                                      const WellState& well_state)
     {
+        // Suppress warnings about "unused parameters".
+        static_cast<void>(dt);
+        static_cast<void>(well_state);
+
         const int nc = grid_.number_of_cells;
         const int np = state.numPhases();
         const int nw = wells_.number_of_wells;