Commit 9f03ca915 removed the only COPYTUP() call that could reach
copytup_index() in practice, making copytup_index() dead code.
The attached patch removes this dead code, in line with the existing
copytup_datum() case, where tuplesort.c also doesn't directly support
COPYTUP() (due to similar considerations around memory management).
--
Peter Geoghegan