Fix yacc failures in preproc.y.
Fix yacc failures in preproc.y.

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