Initial NPN3 finder with MUX and MAJ finder.

src/sat/CMakeLists.txt

@@ -26,6 +26,7 @@ z3_add_component(sat
     sat_lut_finder.cpp
     sat_model_converter.cpp
     sat_mus.cpp
+    sat_npn3_finder.cpp
     sat_parallel.cpp
     sat_prob.cpp
     sat_probing.cpp

src/sat/sat_solver.h

@@ -220,6 +220,7 @@ namespace sat {
         friend class xor_finder;
         friend class aig_finder;
         friend class lut_finder;
+        friend class npn3_finder;
     public:
         solver(params_ref const & p, reslimit& l);
         ~solver() override;