Invalid suggestion when attempting to call async closure

[Aaron1011]

The following snippet:

#![feature(async_await)]

fn main() {
    async || ({
    })();
}

produces the following error:

error[E0618]: expected function, found `()`
 --> src/main.rs:4:14
  |
4 |        async || ({
  |   ______________^
  |  |______________|
  | ||
5 | ||     })();
  | ||______^_- call expression requires function
  | |_______|
  | 
help: if you meant to create this closure and immediately call it, surround the closure with parenthesis
  |
4 |     async || (({
5 |     }))();
  |

However, applying this suggestion doesn't actually fix the error. Instead, it simply causes a new suggestion to be produced - this time with three parentheses (e.g. ((() instead of two.

[Centril]

Labeling as deferred since async closures are not getting stabilized in the MVP.

[compiler-errors]

This is fixed.