Typeclass instances not imported.

[Brian W Bush]

If an Agda module only contains typeclass instances (i.e., orphans), then agda2hs code in other modules do not have an import statement generated for the module with the instances.

Here is an example that shows the workaround for the missing import:

open import Peras.QCD.Types.Instances

{-# FOREIGN AGDA2HS
import Peras.QCD.Types.Instances ()
#-}