remove index_type()

This removes index_type(), and the last remaining user.  The function has
been deprecated since January 2022.

Author: kroening

src/goto-symex/shadow_memory_util.cpp

@@ -475,7 +475,7 @@ exprt compute_or_over_bytes(
       for(mp_integer index = 0; index < size; ++index)
       {
         extract_bytes_of_expr(
-          index_exprt(expr, from_integer(index, index_type())),
+          index_exprt(expr, from_integer(index, array_type.index_type())),
           field_type,
           ns,
           log,

src/util/c_types.cpp

@@ -19,11 +19,6 @@ bitvector_typet c_index_type()
   return signed_size_type();
 }
 
-bitvector_typet index_type()
-{
-  return c_index_type();
-}
-
 signedbv_typet signed_int_type()
 {
   signedbv_typet result(config.ansi_c.int_width);

src/util/c_types.h

@@ -479,10 +479,6 @@ inline code_with_contract_typet &to_code_with_contract_type(typet &type)
   return static_cast<code_with_contract_typet &>(type);
 }
 
-DEPRECATED(
-  SINCE(2022, 1, 13, "use c_index_type() or array_typet::index_type() instead"))
-bitvector_typet index_type();
-
 bitvector_typet c_index_type();
 signedbv_typet signed_int_type();
 unsignedbv_typet unsigned_int_type();