As visible on seawasp and locally (16/main branch nightly packages),
they decided to start warning about these casts with a new strict
variant of the warning. Their discussion:
https://reviews.llvm.org/D134831
There are also a few other cases unrelated to this thread's original
problem, for example casts involving pg_funcptr_t, HashCompareFunc. I
guess our options would be to turn that warning off, or reconsider and
try shoving the cast of "generic" arguments pointers down into the
functions?