Improve release note text about set-returning-function changes.
Improve release note text about set-returning-function changes.

Paul Ramsey griped about this awhile ago, but I'd been holding fire
on changing it until we settled what to do about the CASE/COALESCE
issue.

Discussion: 5db3df9b9a5d27a0b1325b3f394fc36074b767cf@mail.gmail.com

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