Update obsolete comment describing ExecDelete(), per Simon Riggs.
Update obsolete comment describing ExecDelete(), per Simon Riggs.

CraigHarris/gpdb,techdragon/Postgres-XL,cjcjameson/gpdb,chrishajas/gpdb,xuegang/gpdb,yazun/postgres-xl,royc1/gpdb,foyzur/gpdb,cjcjameson/gpdb,tpostgres-projects/tPostgres,ashwinstar/gpdb,foyzur/gpdb,Quikling/gpdb,ovr/postgres-xl,ahachete/gpdb,postmind-net/postgres-xl,arcivanov/postgres-xl,xinzweb/gpdb,rubikloud/gpdb,xinzweb/gpdb,randomtask1155/gpdb,Chibin/gpdb,zaksoup/gpdb,royc1/gpdb,Chibin/gpdb,Quikling/gpdb,janebeckman/gpdb,techdragon/Postgres-XL,janebeckman/gpdb,ashwinstar/gpdb,ahachete/gpdb,cjcjameson/gpdb,0x0FFF/gpdb,kmjungersen/PostgresXL,tangp3/gpdb,50wu/gpdb,greenplum-db/gpdb,lisakowen/gpdb,lintzc/gpdb,ashwinstar/gpdb,atris/gpdb,0x0FFF/gpdb,xinzweb/gpdb,cjcjameson/gpdb,rubikloud/gpdb,foyzur/gpdb,yuanzhao/gpdb,Postgres-XL/Postgres-XL,CraigHarris/gpdb,lisakowen/gpdb,CraigHarris/gpdb,ahachete/gpdb,oberstet/postgres-xl,tpostgres-projects/tPostgres,rubikloud/gpdb,royc1/gpdb,janebeckman/gpdb,lisakowen/gpdb,tangp3/gpdb,edespino/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,50wu/gpdb,Chibin/gpdb,randomtask1155/gpdb,CraigHarris/gpdb,snaga/postgres-xl,foyzur/gpdb,lintzc/gpdb,Quikling/gpdb,Chibin/gpdb,randomtask1155/gpdb,atris/gpdb,janebeckman/gpdb,edespino/gpdb,yuanzhao/gpdb,atris/gpdb,zeroae/postgres-xl,Quikling/gpdb,rubikloud/gpdb,lisakowen/gpdb,atris/gpdb,rvs/gpdb,xuegang/gpdb,xuegang/gpdb,edespino/gpdb,jmcatamney/gpdb,lpetrov-pivotal/gpdb,0x0FFF/gpdb,lpetrov-pivotal/gpdb,janebeckman/gpdb,yuanzhao/gpdb,oberstet/postgres-xl,jmcatamney/gpdb,kmjungersen/PostgresXL,ahachete/gpdb,postmind-net/postgres-xl,kmjungersen/PostgresXL,Quikling/gpdb,CraigHarris/gpdb,Quikling/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,chrishajas/gpdb,atris/gpdb,0x0FFF/gpdb,randomtask1155/gpdb,postmind-net/postgres-xl,xuegang/gpdb,ashwinstar/gpdb,kaknikhil/gpdb,xinzweb/gpdb,edespino/gpdb,tangp3/gpdb,adam8157/gpdb,chrishajas/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,snaga/postgres-xl,arcivanov/postgres-xl,edespino/gpdb,rubikloud/gpdb,ahachete/gpdb,ahachete/gpdb,randomtask1155/gpdb,ashwinstar/gpdb,royc1/gpdb,janebeckman/gpdb,zeroae/postgres-xl,rvs/gpdb,50wu/gpdb,royc1/gpdb,yuanzhao/gpdb,kmjungersen/PostgresXL,kaknikhil/gpdb,tangp3/gpdb,greenplum-db/gpdb,foyzur/gpdb,lpetrov-pivotal/gpdb,Chibin/gpdb,zeroae/postgres-xl,tpostgres-projects/tPostgres,50wu/gpdb,adam8157/gpdb,ahachete/gpdb,CraigHarris/gpdb,arcivanov/postgres-xl,CraigHarris/gpdb,lintzc/gpdb,zaksoup/gpdb,lpetrov-pivotal/gpdb,Quikling/gpdb,snaga/postgres-xl,kaknikhil/gpdb,chrishajas/gpdb,postmind-net/postgres-xl,tpostgres-projects/tPostgres,rvs/gpdb,greenplum-db/gpdb,chrishajas/gpdb,yuanzhao/gpdb,xinzweb/gpdb,edespino/gpdb,zaksoup/gpdb,pavanvd/postgres-xl,randomtask1155/gpdb,greenplum-db/gpdb,lpetrov-pivotal/gpdb,rvs/gpdb,0x0FFF/gpdb,rubikloud/gpdb,adam8157/gpdb,lisakowen/gpdb,pavanvd/postgres-xl,oberstet/postgres-xl,randomtask1155/gpdb,xuegang/gpdb,kaknikhil/gpdb,ovr/postgres-xl,lpetrov-pivotal/gpdb,0x0FFF/gpdb,cjcjameson/gpdb,lpetrov-pivotal/gpdb,Quikling/gpdb,rvs/gpdb,Chibin/gpdb,adam8157/gpdb,zeroae/postgres-xl,ahachete/gpdb,postmind-net/postgres-xl,lisakowen/gpdb,ovr/postgres-xl,xinzweb/gpdb,xinzweb/gpdb,janebeckman/gpdb,lintzc/gpdb,tangp3/gpdb,cjcjameson/gpdb,xuegang/gpdb,greenplum-db/gpdb,arcivanov/postgres-xl,Quikling/gpdb,zaksoup/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,yazun/postgres-xl,Postgres-XL/Postgres-XL,cjcjameson/gpdb,greenplum-db/gpdb,zaksoup/gpdb,zaksoup/gpdb,atris/gpdb,50wu/gpdb,royc1/gpdb,atris/gpdb,Postgres-XL/Postgres-XL,zeroae/postgres-xl,randomtask1155/gpdb,50wu/gpdb,foyzur/gpdb,xuegang/gpdb,Chibin/gpdb,lintzc/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,foyzur/gpdb,kaknikhil/gpdb,adam8157/gpdb,Quikling/gpdb,yazun/postgres-xl,kaknikhil/gpdb,oberstet/postgres-xl,adam8157/gpdb,snaga/postgres-xl,jmcatamney/gpdb,kaknikhil/gpdb,rvs/gpdb,rvs/gpdb,rubikloud/gpdb,greenplum-db/gpdb,lisakowen/gpdb,foyzur/gpdb,pavanvd/postgres-xl,tpostgres-projects/tPostgres,janebeckman/gpdb,cjcjameson/gpdb,kaknikhil/gpdb,Chibin/gpdb,edespino/gpdb,arcivanov/postgres-xl,zaksoup/gpdb,yuanzhao/gpdb,snaga/postgres-xl,rubikloud/gpdb,xinzweb/gpdb,edespino/gpdb,lintzc/gpdb,lintzc/gpdb,jmcatamney/gpdb,adam8157/gpdb,cjcjameson/gpdb,CraigHarris/gpdb,oberstet/postgres-xl,yuanzhao/gpdb,chrishajas/gpdb,CraigHarris/gpdb,pavanvd/postgres-xl,50wu/gpdb,janebeckman/gpdb,lisakowen/gpdb,0x0FFF/gpdb,ovr/postgres-xl,rvs/gpdb,yazun/postgres-xl,xuegang/gpdb,tangp3/gpdb,atris/gpdb,jmcatamney/gpdb,0x0FFF/gpdb,arcivanov/postgres-xl,50wu/gpdb,edespino/gpdb,lpetrov-pivotal/gpdb,tangp3/gpdb,kmjungersen/PostgresXL,pavanvd/postgres-xl,kaknikhil/gpdb,Chibin/gpdb,Postgres-XL/Postgres-XL,chrishajas/gpdb,chrishajas/gpdb,royc1/gpdb,xuegang/gpdb,janebeckman/gpdb,jmcatamney/gpdb,Chibin/gpdb,Postgres-XL/Postgres-XL,adam8157/gpdb,ovr/postgres-xl,rvs/gpdb,jmcatamney/gpdb,zaksoup/gpdb,tangp3/gpdb,lintzc/gpdb,rvs/gpdb,royc1/gpdb,edespino/gpdb,ashwinstar/gpdb,techdragon/Postgres-XL,lintzc/gpdb,kaknikhil/gpdb,yazun/postgres-xl