Fix for bug 3454270: cache lookup error on array selection
Fix for bug 3454270: cache lookup error on array selection

SELECT on an array element was failing due to an agument value
not taken into account by op_mergejoinable.

Patch by sch19831106, code realignment and review by me.

arcivanov/postgres-xl,Postgres-XL/Postgres-XL,Postgres-XL/Postgres-XL,oberstet/postgres-xl,postmind-net/postgres-xl,techdragon/Postgres-XL,pavanvd/postgres-xl,yazun/postgres-xl,Postgres-XL/Postgres-XL,postmind-net/postgres-xl,yazun/postgres-xl,pavanvd/postgres-xl,techdragon/Postgres-XL,oberstet/postgres-xl,pavanvd/postgres-xl,arcivanov/postgres-xl,postmind-net/postgres-xl,ovr/postgres-xl,kmjungersen/PostgresXL,arcivanov/postgres-xl,yazun/postgres-xl,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,kmjungersen/PostgresXL,snaga/postgres-xl,kmjungersen/PostgresXL,zeroae/postgres-xl,postmind-net/postgres-xl,yazun/postgres-xl,arcivanov/postgres-xl,zeroae/postgres-xl,ovr/postgres-xl,oberstet/postgres-xl,zeroae/postgres-xl,pavanvd/postgres-xl,zeroae/postgres-xl,kmjungersen/PostgresXL,arcivanov/postgres-xl,ovr/postgres-xl,Postgres-XL/Postgres-XL,postmind-net/postgres-xl,ovr/postgres-xl,snaga/postgres-xl,zeroae/postgres-xl,oberstet/postgres-xl,ovr/postgres-xl,snaga/postgres-xl,techdragon/Postgres-XL,oberstet/postgres-xl,snaga/postgres-xl,techdragon/Postgres-XL,snaga/postgres-xl,pavanvd/postgres-xl,kmjungersen/PostgresXL,yazun/postgres-xl,arcivanov/postgres-xl