Put undef's before extern declarations that need 'em, per Andrew Dunstan.
Put undef's before extern declarations that need 'em, per Andrew Dunstan.

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