attempt number cast simplification after substitution

src/Convert/Simplify.hs

@@ -49,14 +49,15 @@ pattern SimpleVector :: Signing -> Integer -> Integer -> Type
 pattern SimpleVector sg l r <- IntegerVector _ sg [(RawNum l, RawNum r)]
 
 insertExpr :: Identifier -> Expr -> Scoper Expr ()
-insertExpr ident (Cast (Left (SimpleVector sg l r)) (Number n)) =
-    insertExpr ident $ Number $ numberCast signed size n
+insertExpr ident expr = do
+    expr' <- substituteExprM expr
+    case expr' of
+        Cast (Left (SimpleVector sg l r)) (Number n) ->
+            insertElem ident $ Number $ numberCast signed size n
             where
                 signed = sg == Signed
                 size = fromIntegral $ abs $ l - r + 1
-insertExpr ident expr = do
-    expr' <- substituteExprM expr
-    when (isSimpleExpr expr') $ insertElem ident expr'
+        _ -> when (isSimpleExpr expr') $ insertElem ident expr'
 
 isSimpleExpr :: Expr -> Bool
 isSimpleExpr Number{}  = True