Preserve AND/OR flatness during eval_const_expressions().  This seems a useful improvement in any case, and it keeps the new logic for restrictinfo structures happy.  Per report from Kris Jurka.
Preserve AND/OR flatness during eval_const_expressions().  This seems a
useful improvement in any case, and it keeps the new logic for restrictinfo
structures happy.  Per report from Kris Jurka.

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