Hi,
REL_14_STABLE and REL_15_STABLE have commit de8feb1f3, which turned on
-Wcast-function-type, but don't have commit 101c37cd, which disabled
-Wcast-function-type-strict as we agreed to do[1]. I noticed this on
my local system that has clang 18 as compiler, but you can see it on
any build farm animal using clang 16+.
So I propose to back-patch 101c37cd to those two branches.
[1] https://www.postgresql.org/message-id/flat/CA%2BhUKGKpHPDTv67Y%2Bs6yiC8KH5OXeDg6a-twWo_xznKTcG0kSA%40mail.gmail.com