Let SQL-92 aggregate functions behave the same as SQL-92. Change-Id: Ia2929d1ca6344508bbf772884ea8ef1f39a0e19f Reviewed-on: https://asterix-gerrit.ics.uci.edu/857 Reviewed-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu> Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu> Reviewed-by: Till Westmann <tillw@apache.org>