1. Async functions

    Async functions make it possible to treat functions returning Promise objects as if they were synchronous.

  2. readablestream api: async iterable (supports iteration using `for await ... of`)

  3. javascript operator: await

  4. javascript operator: await: use at module top level

  5. javascript statement: `for await...of`

  6. ecmascript 2022 (es13)