D'Arcy's recent cleanups

src/backend/catalog/index.c

src/backend/catalog/pg_aggregate.c

src/backend/catalog/pg_operator.c

src/backend/catalog/pg_proc.c

src/backend/commands/copy.c

src/backend/executor/execAmi.c

src/backend/executor/nodeIndexscan.c

src/backend/executor/nodeMaterial.c

src/backend/executor/nodeMergejoin.c

src/backend/executor/nodeTee.c

src/include/executor/execdebug.h