Fixed the findMeta function to return emptyMeta when no Meta exists in the given data

Types.hs

@@ -296,8 +296,9 @@ makeConstant m n = A.Literal m A.Int $ A.IntLiteral m (show n)
 
 -- | Find the first Meta value in some part of the AST.
 findMeta :: (Data t, Typeable t) => t -> Meta
-findMeta e = head $ gmapQ (mkQ emptyMeta findMeta') e
+findMeta e = if null metaList then emptyMeta else head metaList
   where
+    metaList = gmapQ (mkQ emptyMeta findMeta') e
     findMeta' :: Meta -> Meta
     findMeta' m = m