message: Simplify `InstanceRef`
diff: @@ -939,7 +939,7 @@ impl InstanceHandle {
  // Set the funcrefs after we've built the instance
  {
  - let instance = instance_ref.as_mut();
  + let instance = instance_ref.as_mut().unwrap();
  let vmctx_ptr = instance.vmctx_ptr();
  instance.funcrefs = build_funcrefs(
  &*instance.module,
  @@ -1237,7 +1237,7 @@ impl InstanceHandle {
  &mut self,
  instance_ptr: *const ffi::c_void,
  ) -> Result<(), Err> {
  - let instance_ref = self.instance.as_mut();
  + let instance_ref = self.instance.as_mut_unchecked();
  for import_function_env in instance_ref.imported_function_envs.values_mut() {
  match import_function_env {
  