Attached is a new port for FLINT. https://flintlib.org/
I was unsure if the .so handling in post-install is the preferred way to fix this up. I also have another version that patches configure.ac that seems to work just as well (by patching the constants to match the port's SHARED_LIBS, removing the install of the symlinks, and using major.minor for the full versioned name).
flint-3.0.1.tar.gz
Description: application/tar-gz