HPCC-8739 Minor improvements to IR output for help with debugging

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #3931 from ghalliday/issue8739

HPCC-8739 Minor improvements to IR output for help with debugging

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>