FFI function pointers with unlifted argument types
I noticed today that GHC disallows using the function pointer
wrapper facilities when the function in question has any unlifted arguments. For example:
type KafkaLog = Addr# -> Int# -> Addr# -> Addr# -> IO () foreign import ccall "wrapper" mkCompare :: KafkaLog -> IO (FunPtr KafkaLog)
UnliftedFFITypes does not address the problem
Allow unlifted types to show up as arguments to wrapped functions when
UnliftedFFITypes is enabled.