New official language extension tokens for GHC 7.8.1

Hello GHC Devs, Which of the language extensions listed in `expectedGhcOnlyExtensions` in http://ghc.haskell.org/trac/ghc/browser/testsuite/tests/driver/T4437.hs#L33 are deemed ready for public consumption in GHC 7.8.1, and can be registered with upstream Cabal now (maybe even for the upcoming 1.18.0 release)? Related: http://ghc.haskell.org/trac/ghc/ticket/8176 Cheers, hvr