Added a smoke test for local scopes

regression/orig/test056.log

@@ -0,0 +1 @@
+> > > 8

regression/test056.expr

@@ -0,0 +1,8 @@
+fun test (a, b, c) {
+  local x = a + b, y = b + c;
+  {local e = x + y;
+   return e
+  }
+}
+
+write (test (read (), read (), read ()))

regression/test056.input

@@ -0,0 +1,3 @@
+1
+2
+3

src/Language.ml

@@ -556,7 +556,7 @@ module Expr =
            let vars, body =
              List.fold_left
                (fun (vs, bd) -> function
-                | (name, `Variable value) -> name :: vs, (match value with None -> bd | Some v -> Seq (Assign (Var name, v), bd))
+                | (name, `Variable value) -> name :: vs, (match value with None -> bd | Some v -> Seq (Assign (Ref name, v), bd))
                 | _                       -> invalid_arg "function"
                )
                ([], expr)