One more case of inlining breaking async/await

[cknitt]

This is similar to the already fixed case in #5754. But it still occurs in 10.1.

external ignorePromise: promise<'a> => unit = "%identity"

let wrapSomethingAsync = () =>
  (
    async () => {
      let test = await Js.Promise.resolve("Test")
      Js.log(test)
    }
  )()->ignorePromise

compiles to

function wrapSomethingAsync(param) {
  var test = await Promise.resolve("Test");
  console.log(test);
}

which is invalid because the function is not marked as async.