Improve outer-join-deduction logic to be able to propagate equalities through multiple join clauses.
Improve outer-join-deduction logic to be able to propagate equalities
through multiple join clauses.

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