Fix most build errors

src/compiler/GF/Compile/GeneratePMCFG.hs

@@ -196,6 +196,9 @@ newtype CnvMonad a = CM {unCM :: SourceGrammar
                               -> ([ProtoFCat],[Symbol])
                               -> Branch b}
 
+instance MonadFail CnvMonad where
+  fail = bug
+
 instance Applicative CnvMonad where
   pure = return
   (<*>) = ap

src/compiler/GF/Compile/Update.hs

@@ -29,7 +29,7 @@ import Control.Monad
 import GF.Text.Pretty
 
 -- | combine a list of definitions into a balanced binary search tree
-buildAnyTree :: Monad m => ModuleName -> [(Ident,Info)] -> m (Map.Map Ident Info)
+buildAnyTree :: MonadFail m => ModuleName -> [(Ident,Info)] -> m (Map.Map Ident Info)
 buildAnyTree m = go Map.empty
   where
     go map []         = return map