message: make func clonable
diff: @@ -216,6 +216,7 @@ pub struct DynamicFunc<'a> {
  unsafe impl<'a> Send for DynamicFunc<'a> {}
  /// Represents a function that can be used by WebAssembly.
  +#[derive(Clone)]
  pub struct Func<'a, Args = (), Rets = (), Inner: Kind = Wasm> {
  inner: Inner,
  