Test patch for partitionwise join with partitioned tables containingdefault partition

As of now partition_join.sql is not having test cases covering cases
where partition table have default partition, attaching a small test
case patch to cover those.

Here is a link of previous discussion :

As found by Thomas, The regression test currently fails with v4 patch because a
redundant Result node has been removed from a query plan. here is the updated

v5 patch fixing this.

Thanks & Regards,

Rajkumar Raghuwanshi