IN(NULL) yields different results with prepared statements

[dekimir]

When NULL is a member of the IN(...) tuple, it doesn't match any rows, even if the field value is NULL:

cqlsh:ks> CREATE TABLE t (p int PRIMARY KEY, r int);
cqlsh:ks> INSERT INTO t(p) VALUES (1);
cqlsh:ks> SELECT * FROM t WHERE r IN ( 99, null ) ALLOW FILTERING ;

But when this NULL is supplied via a prepared statement, it matches NULL fields. The following test fails:

SEASTAR_TEST_CASE(in_null) {
    return do_with_cql_env([](cql_test_env& e) {
        return seastar::async([&e] {
            cquery_nofail(e, "create table t (p int primary key, r int)");
            cquery_nofail(e, "insert into t(p) values (1)");
            require_rows(e, "select p from t where r in (99, null) allow filtering", {});
            auto stmt = e.prepare("select p from t where r in ? allow filtering").get0();
            auto list_type = list_type_impl::get_instance(int32_type, true);
            auto tuple_with_null = list_type->decompose(
                    make_list_value(list_type, {99, data_value::make_null(int32_type)}));
            require_rows(e, stmt, {cql3::raw_value::make_value(std::move(tuple_with_null))}, {});
        });
    });
}

This is inconsistent. The prepared-statement behaviour should match that of inlined CQL.

/cc @alecco

[avikivity]

Minor, not backporting.