Moving refined_string_type to util

This is a more appropriate location for this module since it's used
both in the preprocessing of goto-programs and the string solver.

Author: romainbrenguier

src/goto-programs/string_refine_preprocess.cpp

@@ -14,10 +14,9 @@ Date:   September 2016
 #include <util/pointer_offset_size.h>
 #include <util/prefix.h>
 #include <util/string_expr.h>
+#include <util/refined_string_type.h>
 #include <util/fresh_symbol.h>
 #include <goto-programs/class_identifier.h>
-// TODO: refined_string_type should be moved to util
-#include <solvers/refinement/refined_string_type.h>
 #include <java_bytecode/java_types.h>
 
 #include "string_refine_preprocess.h"

src/solvers/refinement/string_constraint.h

@@ -15,7 +15,7 @@ Author: Romain Brenguier, [email protected]
 
 #include <langapi/language_ui.h>
 #include <solvers/refinement/bv_refinement.h>
-#include <solvers/refinement/refined_string_type.h>
+#include <util/refined_string_type.h>
 
 class string_constraintt: public exprt
 {

src/solvers/refinement/string_constraint_generator.h

@@ -14,7 +14,7 @@ Author: Romain Brenguier, [email protected]
 #define CPROVER_SOLVERS_REFINEMENT_STRING_CONSTRAINT_GENERATOR_H
 
 #include <util/string_expr.h>
-#include <solvers/refinement/refined_string_type.h>
+#include <util/refined_string_type.h>
 #include <solvers/refinement/string_constraint.h>
 
 class string_constraint_generatort

src/solvers/refinement/refined_string_type.cpp renamed to src/util/refined_string_type.cpp

@@ -10,8 +10,8 @@ Author: Romain Brenguier, [email protected]
 
 \*******************************************************************/
 
-#ifndef CPROVER_SOLVERS_REFINEMENT_REFINED_STRING_TYPE_H
-#define CPROVER_SOLVERS_REFINEMENT_REFINED_STRING_TYPE_H
+#ifndef CPROVER_UTIL_REFINED_STRING_TYPE_H
+#define CPROVER_UTIL_REFINED_STRING_TYPE_H
 
 #include <util/std_types.h>
 #include <util/std_expr.h>