added printTree for monomorphizer

test_program.crf

@@ -1,20 +1,5 @@
-data List () where {
-    Nil : List ()
-    Cons : Int -> List () -> List ()
-};
+id x = x;
 
-main = case Nil of {
-    Nil => 0 ;
-    Cons a _ => a ;
-};
+const x y = x ;
 
--- length : List () -> Int ;
--- length xs = case xs of {
---     Nil => 0;
---     Cons _ xs => 1 + length xs ;
--- };
-
---sum xs = case xs of {
---    Nil => 0 ;
---    Cons a xs => a + main xs ;
---};
+main = const (id 0) (id 'a') ;