Add `return` method test

test/built-ins/AsyncFromSyncIteratorPrototype/return/absent-value-not-passed.js

@@ -0,0 +1,43 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.return
+description: >
+  `return` method does not pass absent `value`.
+info: |
+  %AsyncFromSyncIteratorPrototype%.return ( value )
+
+  [...]
+  8. If value is present, then
+    [...]
+  9. Else,
+    a. Let result be Call(return, syncIterator).
+  [...]
+flags: [async]
+features: [async-iteration]
+---*/
+
+var returnArgumentsLength;
+var syncIterator = {
+  [Symbol.iterator]() {
+    return this;
+  },
+  next() {
+    return {done: false};
+  },
+  return() {
+    returnArgumentsLength = arguments.length;
+    return {done: true};
+  },
+};
+
+var asyncIterator = (async function* () {
+  yield* syncIterator;
+})();
+
+asyncIterator.next().then(function() {
+  return asyncIterator.return();
+}).then(function() {
+  assert.sameValue(returnArgumentsLength, 0);
+}).then($DONE, $DONE);