add bounded-int and pb2bv solvers to fd_solver, use sorting networks for pb2bv rewriter when applicable, hoist to pb2bv_rewriter module and remove it from the pb2bv_tactic

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

contrib/cmake/src/ast/rewriter/CMakeLists.txt

@@ -9,14 +9,15 @@ z3_add_component(rewriter
     datatype_rewriter.cpp
     der.cpp
     dl_rewriter.cpp
+    enum2bv_rewriter.cpp
     expr_replacer.cpp
     expr_safe_replace.cpp
     factor_rewriter.cpp
-    fd_rewriter.cpp
     fpa_rewriter.cpp
     label_rewriter.cpp
     mk_simplified_app.cpp
     pb_rewriter.cpp
+    pb2bv_rewriter.cpp
     quant_hoist.cpp
     rewriter.cpp
     seq_rewriter.cpp