Remove IndexInfo.ii_OpclassOptions field
It is unnecessary to include this field in IndexInfo. It is only used
by DDL code, not during execution. It is really only used to pass
local information around between functions in index.c and indexcmds.c,
for which it is clearer to use local variables, like in similar cases.
Discussion: https://www.postgresql.org/message-id/flat/
f84640e3-00d3-5abd-3f41-
e6a19d33c40b@eisentraut.org