Typehinting async functions before arg vector doesn't (always) work

Describe the bug

Examples:

This one works

(defn async-int ^#/(Future int) []
  (dasync/Future.value 1))

This one doesn't

(defn ^:async async-int ^#/(Future int) []
  (dasync/Future.value 1))

Error: A value of type 'FutureOr<Future<int>>' can't be returned from an async function with return type 'Future<int>'.
 - 'Future' is from 'dart:async'.
return ((da.Future.value(1, )) as da.FutureOr<dc.Future<dc.int>>);

Also, sometimes removing ^:async doesn't help:

(defn async-int-after-job ^#/(Future int) []
  (let [value 1
        job (dasync/Future.value true)]
    (await job)
    (dasync/Future.value value)))

Error: A value of type 'FutureOr<Future<int>>' can't be returned from an async function with return type 'Future<int>'.
 - 'Future' is from 'dart:async'.
return ($1 as da.FutureOr<dc.Future<dc.int>>);

But removing type hint (or moving it before name) helps

(defn ^#/(Future int) async-int-after-job []
  (let [value 1
        job (dasync/Future.value true)]
    (await job)
    (dasync/Future.value value)))

Reproduce the three examples in the issue and compare the generated Dart errors, especially with ^:async, return type hints, and await. Trace the compiler handling for these forms; the fix is complete when the affected examples compile with the intended Future return type.