Merged patch series from Piotr Sarna:
Calculating the select statement for given view_info structure
used to work fine, but once local indexes were introduced, a subtle
bug appeared: the legacy token column does not exist in local indexes
and a valid clustering key column was omitted instead.
That results in potentially incorrect partition slices being used later
in read-before-write.
There's a long term plan for removing select_statement from
view info altogether, but nonetheless the bug needs to be fixed first.
Branch: master, 3.1
Tests: unit(dev) + manual confirmation that a correct legacy column is picked
765dc86de4