Add more new language extensions from GHC

Cabal/Language/Haskell/Extension.hs

@@ -747,10 +747,24 @@ data KnownExtension =
   -- | Enable explicit type applications with the syntax @id \@Int@.
   | TypeApplications
 
+  -- | Dissolve the distinction between types and kinds, allowing the compiler
+  -- to reason about kind equality and therefore enabling GADTs to be promoted
+  -- to the type-level.
+  | TypeInType
+
+  -- | Allow recursive (and therefore undecideable) super-class relationships.
+  | UndecidableSuperClasses
+
   -- | A temporary extension to help library authors check if their
   -- code will compile with the new planned desugaring of fail.
   | MonadFailDesugaring
 
+  -- | A subset of @TemplateHaskell@ including only quasi-quoting.
+  | TemplateHaskellQuotes
+
+  -- | Allows use of the @#label@ syntax.
+  | OverloadedLabels
+
   deriving (Generic, Show, Read, Eq, Ord, Enum, Bounded, Typeable, Data)
 
 instance Binary KnownExtension