[COMMITTERS] pgsql: Expand coverage of parallel gather merge a bit.

Expand coverage of parallel gather merge a bit. Previously paths reaching heap_compare_slots weren't covered. Author: Rushabh Lathia Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAGPqQf3C+3PBujb+7m=ceWeii4-vBY=xs99ljzrpkpefvzj...@mail.gmail.com https://postgr.es/m/2

[COMMITTERS] pgsql: Expand coverage of parallel gather merge a bit.

Expand coverage of parallel gather merge a bit. Previously paths reaching heap_compare_slots weren't covered. Author: Rushabh Lathia Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAGPqQf3C+3PBujb+7m=ceWeii4-vBY=xs99ljzrpkpefvzj...@mail.gmail.com https://postgr.es/m/2