HPCC-11925 Add some smart join tests to the regression suite

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #24 from ghalliday/issue11925

HPCC-11925 Add some smart join tests to the regression suite

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>