[Bug d/111628] D: concurrency.d hangs on macOS 13 (Ventura) and 14 (Sonoma).

[ro at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111628

--- Comment #2 from Rainer Orth <ro at gcc dot gnu.org> ---
I take that back: during the last two weeks, the test looped again.  It would
be good to skip it on the affected Darwin versions, otherwise tests accumulate
over time (maybe unnoticed), consuming cpu time for nothing.