Drop string_non_empty field for string refinement

Author: romainbrenguier

src/cbmc/cbmc_solvers.cpp

@@ -178,7 +178,6 @@ std::unique_ptr<cbmc_solverst::solvert> cbmc_solverst::get_string_refinement()
   info.ui=ui;
   if(options.get_bool_option("string-max-length"))
     info.string_max_length=options.get_signed_int_option("string-max-length");
-  info.string_non_empty=options.get_bool_option("string-non-empty");
   info.trace=options.get_bool_option("trace");
   if(options.get_bool_option("max-node-refinement"))
     info.max_node_refinement=

src/solvers/refinement/string_refinement.h

@@ -49,8 +49,6 @@ class string_refinementt final: public bv_refinementt
   struct configt
   {
     std::size_t refinement_bound=0;
-    /// Make non-deterministic character arrays have at least one character
-    bool string_non_empty=false;
     /// Concretize strings after solver is finished
     bool trace=false;
     bool use_counter_example=true;