Outer attributes of generic type / lifetime parameter not respected in async trait async function definition.

[jymchng]

Hi sir(s)

Thank you for the awesome crate and also for many other crates you (and your team) had contributed to the Rust ecosystem!

Consider this snippet:

use {async_trait::async_trait}; // 0.1.86

#[async_trait]
trait AsyncTrait {
    
    async fn async_fn<#[cfg(test)] T>(#[cfg(test)] t: T) {
        #[cfg(test)]
        let _ = t;
    }
}

trait SyncTrait {
    
    fn async_fn<#[cfg(test)] T>(#[cfg(test)] t: T) {
        #[cfg(test)]
        let _ = t;
    }
}

Playground

For the async function definition async fn async_fn<#[cfg(test)] T>(#[cfg(test)] t: T) {, it seems that #[async_trait] attribute macro does not respect the outer attribute #[cfg(test)] in the generic type parameter 'slot', i.e. <#[cfg(test)] T>.

I am not sure if this is a bug or intended.

Thank you.