Replace java_int_type by tyep deduced from array

This makes the function more robust and avoid dependencies on java
types.

Author: romainbrenguier

src/solvers/refinement/string_refinement.cpp

@@ -1223,6 +1223,7 @@ static exprt substitute_array_access(
     &symbol_generator)
 {
   const typet &char_type = array_expr.type().subtype();
+  const typet &index_type = to_array_type(array_expr.type()).size().type();
   const std::vector<exprt> &operands = array_expr.operands();
 
   exprt result = symbol_generator("out_of_bound_access", char_type);
@@ -1231,7 +1232,7 @@ static exprt substitute_array_access(
   {
     // Go in reverse order so that smaller indexes appear first in the result
     const std::size_t pos = operands.size() - 1 - i;
-    const equal_exprt equals(index, from_integer(pos, java_int_type()));
+    const equal_exprt equals(index, from_integer(pos, index_type));
     if(operands[pos].type() != char_type)
     {
       INVARIANT(