Add a CHECK_FOR_INTERRUPTS() in _bt_buildadd().  This fixes problem with not responding to query cancel during the last stage of btree index creation.
Add a CHECK_FOR_INTERRUPTS() in _bt_buildadd().  This fixes problem
with not responding to query cancel during the last stage of btree index
creation.

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