R1:50e809e06f4b

Fix an issue where recurring ghost events could go missing if queried with a limit

Summary:
Ref T11816. Depends on D17644. When you executed a query like "upcoming, limit 5 events" you might match some recurring events starting from, say, a year ago and repeating every month.

We'd then generate the first 5 ghosts for these events (say, last January, February, ... May) and later throw them out, so the correct events in the query window (say, this April) would never get generated.

Instead, generate ghosts…