Omitted # after LANGUAGE pragma causes panic

[viritrilbia]

If the # in the closing #-} after a LANGUAGE pragma is omitted, GHC panics. For example, creating a file containing the single line:

{-# LANGUAGE TypeFamilies -}

and passing it to GHC or GHCi produces:

ghc: panic! (the 'impossible' happened)
  (GHC version 6.10.3 for i386-unknown-linux):
	getOptions'.parseLanguage(1) went past eof token

[simonmar]

dup of #3153