message: fix(api) Restore the `unimplemented!` macro.
diff: @@ -252,12 +252,14 @@ impl Function {
  /// call the trampoline.
  pub fn call(&self, params: &[Val]) -> Result<Box<[Val]>, RuntimeError> {
  let mut results = vec![Val::null(); self.result_arity()];
  +
  match &self.definition {
  FunctionDefinition::Wasm(wasm) => {
  self.call_wasm(&wasm, params, &mut results)?;
  }
  - _ => {} // _ => unimplemented!("The host is unimplemented"),
  + _ => unimplemented!("The function definition isn't supported for the moment"),
  }
  +
  Ok(results.into_boxed_slice())
  }
  