This module re-exports the Extension type along with an orphan Binary instance for it.

Note that the ghc-boot package has a large set of dependencies; for this reason the Extension type itself is defined in the GHC.LanguageExtensions.Type module provided by the ghc-boot-th package, which has no dependencies outside of base. For this reason template-haskell depends upon ghc-boot-th, not ghc-boot.