message: Simplified get logic
diff: @@ -597,16 +597,10 @@ impl Instance {
  let table = self.get_table(table_index);
  let passive_elements = self.passive_elements.borrow();
  - let elem = passive_elements.get(elem_index).map_or_else(
  - || -> &[VMCallerCheckedAnyfunc] { &[] },
  - |e| {
  - if let Some(e) = e {
  - &**e
  - } else {
  - &[]
  - }
  - },
  - );
  + let elem = passive_elements
  + .get(elem_index)
  + .and_then(|e| e.as_ref().map(|e| &**e))
  + .unwrap_or(&[]);
  if src
  .checked_add(len)
  @@ -723,13 +717,10 @@ impl Instance {
  let memory = self.get_memory(memory_index);
  let passive_data = self.passive_data.borrow();
  - let data = passive_data.get(data_index).map_or(&[][..], |data| {
  - if let Some(data) = data {
  - &**data
  - } else {
  - &[][..]
  - }
  - });
  + let data = passive_data
  + .get(data_index)
  + .and_then(|data| data.as_ref().map(|d| &**d))
  + .unwrap_or(&[][..]);
  if src
  .checked_add(len)
  