message: Use RAII for instantiation lock
diff: @@ -216,15 +216,15 @@ where
  }
  }
  - let lock = instantiation_lock.map(|l| l.lock().unwrap());
  - let wasmer_instance = Box::from(WasmerInstance::new(module, &import_obj).map_err(
  - |original| {
  - VmError::instantiation_err(format!("Error instantiating module: {:?}", original))
  - },
  - )?);
  - if let Some(lock) = lock {
  - drop(lock)
  + let wasmer_instance = Box::from(
  + {
  + let _lock = instantiation_lock.map(|l| l.lock().unwrap());
  + WasmerInstance::new(module, &import_obj)
  }
  + .map_err(|original| {
  + VmError::instantiation_err(format!("Error instantiating module: {:?}", original))
  + })?,
  + );
  let instance_ptr = NonNull::from(wasmer_instance.as_ref());
  env.set_wasmer_instance(Some(instance_ptr));
  