[Intl] Add more tests for Intl.Segmenter

Bug: v8:6891
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I623f996c0d80cd23dcad6ffedac993678a2af959
Reviewed-on: https://chromium-review.googlesource.com/c/1289609
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Daniel Ehrenberg <littledan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56830}

test/intl/segmenter/segment-iterator-ownPropertyDescriptor.js

@@ -29,10 +29,47 @@ for (let func of ["segment", "resolvedOptions"]) {
   assertTrue(descriptor.configurable);
 }
 
-let prototype = Object.getPrototypeOf(seg.segment('text'));
+let segmentIterator = seg.segment('text');
+let prototype = Object.getPrototypeOf(segmentIterator);
 for (let func of ["next", "following", "preceding"]) {
   let descriptor = Object.getOwnPropertyDescriptor(prototype, func);
   assertTrue(descriptor.writable);
   assertFalse(descriptor.enumerable);
   assertTrue(descriptor.configurable);
 }
+
+function checkGetterProperty(prototype, property) {
+  let desc = Object.getOwnPropertyDescriptor(prototype, property);
+  assertEquals(`get ${property}`, desc.get.name);
+  assertEquals('function', typeof desc.get)
+  assertEquals(undefined, desc.set);
+  assertFalse(desc.enumerable);
+  assertTrue(desc.configurable);
+}
+
+// Test the descriptor is correct for properties.
+checkGetterProperty(prototype, 'position');
+checkGetterProperty(prototype, 'breakType');
+
+// Test the SegmentIteratorPrototype methods are called with same
+// receiver and won't throw.
+assertDoesNotThrow(() => prototype.next.call(segmentIterator));
+assertDoesNotThrow(() => prototype.following.call(segmentIterator));
+assertDoesNotThrow(() => prototype.preceding.call(segmentIterator));
+
+// Test the SegmentIteratorPrototype methods are called with a different
+// receiver and correctly throw.
+var otherReceivers = [
+    1, 123.45, undefined, null, "string", true, false,
+    Intl, Intl.Segmenter, Intl.Segmenter.prototype,
+    prototype,
+    new Intl.Segmenter(),
+    new Intl.Collator(),
+    new Intl.DateTimeFormat(),
+    new Intl.NumberFormat(),
+];
+for (let rec of otherReceivers) {
+   assertThrows(() => prototype.next.call(rec), TypeError);
+   assertThrows(() => prototype.following.call(rec), TypeError);
+   assertThrows(() => prototype.preceding.call(rec), TypeError);
+}