adding totalizer

src/test/totalizer.cpp

@@ -0,0 +1,25 @@
+#include "opt/totalizer.h"
+#include "ast/ast_pp.h"
+#include "ast/reg_decl_plugins.h"
+#include <iostream>
+
+void tst_totalizer() {
+    std::cout << "totalizer\n";
+    ast_manager m;
+    reg_decl_plugins(m);
+    expr_ref_vector lits(m);
+    for (unsigned i = 0; i < 5; ++i)
+        lits.push_back(m.mk_fresh_const("a", m.mk_bool_sort()));
+    opt::totalizer tot(lits);
+
+    for (unsigned i = 0; i <= 6; ++i) {
+        std::cout << "at least " << i << " ";
+        expr* am = tot.at_least(i);
+        std::cout << mk_pp(am, m) << "\n";        
+    }
+    for (auto& clause : tot.clauses()) {
+        for (auto * l : clause)
+            std::cout << mk_pp(l, m) << " ";
+        std::cout << "\n";
+    }
+}