Drop redundant `{-# LANGUAGE #-}` pragmas

This removes language pragmas from Haskell modules which are implicitly
active with `default-language: Haskell2010`. Specifically, the following
language extension pragmas are removed by this commit:

 - PatternGuards
 - ForeignFunctionInterface
 - EmptyDataDecls
 - NoBangPatterns

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/libraries/base/System/IO.hs b/libraries/base/System/IO.hs
index 93245d39fe..4b247f987d 100644
--- a/libraries/base/System/IO.hs
+++ b/libraries/base/System/IO.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP, NoImplicitPrelude #-}
-{-# LANGUAGE ForeignFunctionInterface #-}
 
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