Minor code rearrangement & doc improvement in eval_const_expressions().
Minor code rearrangement & doc improvement in eval_const_expressions().

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