Patch extra-1.7.12 to adapt to (!?) in base

patches/extra-1.7.12.patch

+diff --git a/src/Data/List/Extra.hs b/src/Data/List/Extra.hs
+index 4b4fbe5..2a476cc 100644
+--- a/src/Data/List/Extra.hs
++++ b/src/Data/List/Extra.hs
+@@ -1,4 +1,5 @@
+-{-# LANGUAGE TupleSections, ConstraintKinds #-}
++{-# LANGUAGE TupleSections, ConstraintKinds, CPP #-}
++{-# OPTIONS_GHC -fno-warn-duplicate-exports #-}
+ 
+ -- | This module extends "Data.List" with extra functions of a similar nature.
+ --   The package also exports the existing "Data.List" functions.
+@@ -156,6 +157,7 @@ lastDef :: a -> [a] -> a
+ lastDef d xs = foldl (\_ x -> x) d xs -- I know this looks weird, but apparently this is the fastest way to do this: https://hackage.haskell.org/package/base-4.12.0.0/docs/src/GHC.List.html#last
+ {-# INLINE lastDef #-}
+ 
++#if __GLASGOW_HASKELL__ < 907
+ -- | A total variant of the list index function `(!!)`.
+ --
+ -- > [2,3,4] !? 1    == Just 3
+@@ -169,6 +171,7 @@ xs !? n
+                                    0 -> Just x
+                                    _ -> r (k-1)) (const Nothing) xs n
+ {-# INLINABLE (!?) #-}
++#endif
+ 
+ -- | A composition of 'not' and 'null'.
+ --