Add IS OF type predicate.
Add IS OF type predicate.

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