Drop explicit TypeSynonymInstances pragma
This is implied by FlexibleInstances in newer GHC releases.
-{-# LANGUAGE FlexibleInstances, ForeignFunctionInterface, ScopedTypeVariables #-}
-
--- In older versions of GHC, FlexibleInstances doesn't imply
--- TypeSynonymInstances, so we need to enable it explicitly.
--- See #29.
-{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE ScopedTypeVariables #-}
module Scripting.Lua
( LuaState
