Dear libraries,

I'm reporting about minor broken link in source comment.
There is a broken link in `libraries/binary/src/Data/Binary/Get.hs`.

--- <http://www.haskell.org/ghc/docs/latest/html/users_guide/pragmas.html#unpack-pragma>
+-- <http://www.haskell.org/ghc/docs/latest/html/users_guide/glasgow_exts.html#unpack-pragma>

Regards,
Takenobu