Test that the sync iterator called via for-await-of closes

when a rejected promise is returned normally by the iterator.

These tests correspond to this normative changes example:
https://docs.google.com/presentation/d/1W9EJoWOvi6jU1A2bwyixzOceoP_ASAeaOYER3Zy9P00/edit#slide=id.g10c9207737d_0_31

test/built-ins/AsyncFromSyncIteratorPrototype/next/iterator-next-result-rejected-promise-close.js

@@ -0,0 +1,65 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.next
+description: next() will reject promise if resolving result promise abrupt completes.
+info: |
+  %AsyncFromSyncIteratorPrototype%.next ( value )
+  ...
+  3. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  4. Let syncIteratorRecord be O.[[SyncIteratorRecord]].
+  5. If value is present, then
+    ...
+  6. Else,
+    a. Let result be IteratorNext(syncIteratorRecord).
+  7. IfAbruptRejectPromise(result, promiseCapability).
+  8. Return ! AsyncFromSyncIteratorContinuation(result, promiseCapability, syncIteratorRecord, true).
+
+  AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )
+  1. Let done be IteratorComplete(result).
+  2. IfAbruptRejectPromise(done, promiseCapability).
+  3. Let value be IteratorValue(result).
+  4. IfAbruptRejectPromise(value, promiseCapability).
+  5. Let valueWrapper be PromiseResolve(%Promise%, value).
+  6. If valueWrapper is an abrupt completion, done is false, and closeOnRejection is true, then
+    a. Set valueWrapper to IteratorClose(syncIteratorRecord, valueWrapper).
+  ...
+  12. If done is true, or if closeOnRejection is false, then
+    ...
+  13. Else,
+    a. Let closeIterator be a new Abstract Closure with parameters (error) that captures syncIteratorRecord and performs the following steps when called:
+        i. Return ? IteratorClose(syncIteratorRecord, ThrowCompletion(error)).
+    b. Let onRejected be CreateBuiltinFunction(closeIterator, 1, "", « »).
+    c. NOTE: onRejected is used to close the Iterator when the "value" property of an IteratorResult object it yields is a rejected promise.
+  14. Perform PerformPromiseThen(valueWrapper, onFulfilled, onRejected, promiseCapability).
+  15. Return promiseCapability.[[Promise]].
+
+
+flags: [async]
+features: [async-iteration]
+includes: [asyncHelpers.js]
+---*/
+
+var finallyCount = 0;
+var caught = false;
+
+function* iterator() {
+  try {
+    yield Promise.reject("reject");
+  } finally {
+    finallyCount += 1;
+  }
+}
+
+asyncTest(async () => {
+  try {
+    for await (const x of iterator());
+  } catch (e) {
+    caught = true;
+    assert.sameValue(e, "reject");
+  }
+
+  assert.sameValue(finallyCount, 1);
+  assert(caught);
+});

test/built-ins/AsyncFromSyncIteratorPrototype/next/next-result-rejected-promise-close.js

@@ -0,0 +1,70 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%asyncfromsynciteratorprototype%.next
+description: next() will reject promise if resolving result promise abrupt completes.
+info: |
+  %AsyncFromSyncIteratorPrototype%.next ( value )
+  ...
+  3. Let promiseCapability be ! NewPromiseCapability(%Promise%).
+  4. Let syncIteratorRecord be O.[[SyncIteratorRecord]].
+  5. If value is present, then
+    ...
+  6. Else,
+    a. Let result be IteratorNext(syncIteratorRecord).
+  7. IfAbruptRejectPromise(result, promiseCapability).
+  8. Return ! AsyncFromSyncIteratorContinuation(result, promiseCapability, syncIteratorRecord, true).
+
+  AsyncFromSyncIteratorContinuation ( result, promiseCapability, syncIteratorRecord, closeOnRejection )
+  1. Let done be IteratorComplete(result).
+  2. IfAbruptRejectPromise(done, promiseCapability).
+  3. Let value be IteratorValue(result).
+  4. IfAbruptRejectPromise(value, promiseCapability).
+  5. Let valueWrapper be PromiseResolve(%Promise%, value).
+  6. If valueWrapper is an abrupt completion, done is false, and closeOnRejection is true, then
+    a. Set valueWrapper to IteratorClose(syncIteratorRecord, valueWrapper).
+  ...
+  12. If done is true, or if closeOnRejection is false, then
+    ...
+  13. Else,
+    a. Let closeIterator be a new Abstract Closure with parameters (error) that captures syncIteratorRecord and performs the following steps when called:
+        i. Return ? IteratorClose(syncIteratorRecord, ThrowCompletion(error)).
+    b. Let onRejected be CreateBuiltinFunction(closeIterator, 1, "", « »).
+    c. NOTE: onRejected is used to close the Iterator when the "value" property of an IteratorResult object it yields is a rejected promise.
+  14. Perform PerformPromiseThen(valueWrapper, onFulfilled, onRejected, promiseCapability).
+  15. Return promiseCapability.[[Promise]].
+
+
+flags: [async]
+features: [async-iteration]
+includes: [asyncHelpers.js]
+---*/
+
+var returnCount = 0;
+var caught = false;
+
+const syncIterator = {
+  [Symbol.iterator]() {
+    return {
+      next() {
+        return { value: Promise.reject("reject"), done: false };
+      },
+      return() {
+        returnCount += 1;
+      }
+    };
+  }
+}
+
+asyncTest(async () => {
+  try {
+    for await (let _ of syncIterator);
+  } catch (e) {
+    caught = true;
+    assert.sameValue(e, "reject");
+  }
+
+  assert.sameValue(returnCount, 1);
+  assert(caught);
+});