Fix async iterator methods not passing absent values tests (#2571)

* Fix `next` method test

* Fix `return` method test

* Drop `throw` method test

%AsyncFromSyncIteratorPrototype%.throw is always called with `value`.

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

@@ -29,10 +29,8 @@ var syncIterator = {
   },
 };
 
-var asyncIterator = (async function* () {
-  yield* syncIterator;
-})();
+(async function () {
+  for await (let _ of syncIterator);
 
-asyncIterator.next().then(function() {
   assert.sameValue(nextArgumentsLength, 0);
-}).then($DONE, $DONE);
+})().then($DONE, $DONE);

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

@@ -32,12 +32,10 @@ var syncIterator = {
   },
 };
 
-var asyncIterator = (async function* () {
-  yield* syncIterator;
-})();
+(async function () {
+  for await (let _ of syncIterator) {
+    break;
+  }
 
-asyncIterator.next().then(function() {
-  return asyncIterator.return();
-}).then(function() {
   assert.sameValue(returnArgumentsLength, 0);
-}).then($DONE, $DONE);
+})().then($DONE, $DONE);

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

@@ -1,45 +0,0 @@
-// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-%asyncfromsynciteratorprototype%.throw
-description: >
-  `throw` method does not pass absent `value`.
-info: |
-  %AsyncFromSyncIteratorPrototype%.throw ( value )
-
-  [...]
-  8. If value is present, then
-    [...]
-  9. Else,
-    a. Let result be Call(throw, syncIterator).
-  [...]
-flags: [async]
-features: [async-iteration]
----*/
-
-var throwArgumentsLength;
-var syncIterator = {
-  [Symbol.iterator]() {
-    return this;
-  },
-  next() {
-    return {done: false};
-  },
-  throw() {
-    throwArgumentsLength = arguments.length;
-    return {done: true};
-  },
-};
-
-var asyncIterator = (async function* () {
-  yield* syncIterator;
-})();
-
-asyncIterator.next().then(function() {
-  return asyncIterator.throw();
-}).then(function(result) {
-  throw new Test262Error("Promise should be rejected, got: " + result.value);
-}, function() {
-  assert.sameValue(throwArgumentsLength, 0);
-}).then($DONE, $DONE);