Add declarations for text, bpchar, and varchar length functions.
Add declarations for text, bpchar, and varchar length functions.

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