. since mid 2017 with 512f41cf, we have been using designated
initializers for array (e.g. "int array[10] = { [5] = 2 }").
+ . since early 2021 with 765dc168882, we have been using variadic
+ macros, mostly for printf-like trace and debug macros.
+
These used to be forbidden, but we have not heard any breakage
report, and they are assumed to be safe.