Add compile flags sample.
Add compile flags sample.

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