Fix assign_datestyle() so that it doesn't misleadingly complain about 'conflicting datestyle specifications' for input that's actually only redundant, such as SET DATESTYLE = MDY, MDY.  Per recent gripe.
Fix assign_datestyle() so that it doesn't misleadingly complain about
'conflicting datestyle specifications' for input that's actually only
redundant, such as SET DATESTYLE = MDY, MDY.  Per recent gripe.

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