`arcmutex!` convenience macro

[amab8901]

Is your feature request related to a problem? Please describe. Frustration lies in the verbosity (and hard-to-readness) of having to write:

let state_of_devices = Arc::new(Mutex::new(STATE_OF_DEVICES.clone()));

Describe the solution you'd like Convenience macro:

let state_of_devices = arcmutex!(STATE_OF_DEVICES.clone());

Describe alternatives you've considered

• The verbose approach
• creating my own crate just for this feature

Additional context I think it would make sense to use a convenience macro for Arc<Mutex<T>> because it's a common pattern.

[Darksonn]

You can define it yourself. It will not be added to Tokio.