No autocompletion for arguments of async functions

[vkurchatkin]

I'm using rls 1.40.0 (5db91c7 2019-10-30) with vscode. I get not autocompletion for s in this code:

async fn test(s: &str) {
}

If I alias s with and explicit annotation, it works fine:

async fn test(s: &str) {
    let s: &str = s;
}

[vkurchatkin]

Works fine on nightly, so probably already fixed