Minor code cleanups, make in_group() check faster.
Minor code cleanups, make in_group() check faster.

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