port bit-blaster to simplifiers

inc_sat_solver uses bit-blaster, card2bv and max_bv_sharing.
By turning these into simplifiers it will be possible to remove
dependencies on tactics and goals in inc_sat_simplifier and instead use a modular and general incremental pre-processing infrastructure.

src/ast/simplifiers/bit_blaster.h

@@ -0,0 +1,51 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    bit_blaster.h
+
+Abstract:
+
+    Apply bit-blasting
+
+Author:
+
+    Leonardo (leonardo) 2011-10-25
+
+--*/
+#include "ast/rewriter/bit_blaster/bit_blaster_rewriter.h"
+#include "ast/ast_pp.h"
+#include "model/model_pp.h"
+#include "ast/rewriter/rewriter_types.h"
+#include "ast/simplifiers/dependent_expr_state.h"
+
+
+class bit_blaster : public dependent_expr_simplifier {
+
+    bit_blaster_rewriter   m_rewriter;
+    unsigned               m_num_steps = 0;
+    params_ref             m_params;
+
+public:
+    bit_blaster(ast_manager & m, params_ref const & p, dependent_expr_state& s):
+        dependent_expr_simplifier(m, s),
+        m_rewriter(m, p) {
+        updt_params(p);
+    }
+
+    void updt_params(params_ref const & p) override;
+    void collect_param_descrs(param_descrs & r) override;
+    void reduce() override;
+    void collect_statistics(statistics& st) const override;
+    void push() override;
+    void pop(unsigned n) override;
+
+    /*
+    * Expose the bit-blaster rewriter so that assumptions and implied bit-vectors can be reconstructed
+    * after bit-blasting.
+    */
+    bit_blaster_rewriter& rewriter() { return m_rewriter; }
+
+};
+