TEMP FIX TO REMOVE WHEN REBASING ON diffblue#4546

Author: Joel Allred

src/solvers/strings/string_constraint_generator_comparison.cpp

@@ -206,12 +206,18 @@ string_constraint_generatort::add_axioms_for_hash_code(
   {
     const symbol_exprt i = fresh_symbol("index_hash", index_type);
     const equal_exprt c1(it.second, hash);
-    const notequal_exprt c2(it.first.length(), str.length());
+    const notequal_exprt c2(
+      array_pool.get_or_create_length(it.first),
+      array_pool.get_or_create_length(str));
     const and_exprt c3(
-      equal_exprt(it.first.length(), str.length()),
+      equal_exprt(
+        array_pool.get_or_create_length(it.first),
+        array_pool.get_or_create_length(str)),
       and_exprt(
         notequal_exprt(str[i], it.first[i]),
-        and_exprt(greater_than(str.length(), i), is_positive(i))));
+        and_exprt(
+          greater_than(array_pool.get_or_create_length(str), i),
+          is_positive(i))));
     hash_constraints.existential.push_back(or_exprt(c1, or_exprt(c2, c3)));
   }
   return {hash, std::move(hash_constraints)};