Check the step 29 of InitializeDateTimeFormat (#2427)

test/intl402/DateTimeFormat/prototype/resolvedOptions/hourCycle-default.js

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+// Copyright 2019 Google Inc. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.DateTimeFormat.prototype.resolvedOptions
+description: >
+  Intl.DateTimeFormat.prototype.resolvedOptions properly
+  reflect hourCycle settings.
+info: |
+  12.4.5 Intl.DateTimeFormat.prototype.resolvedOptions()
+
+  12.1.1 InitializeDateTimeFormat ( dateTimeFormat, locales, options )
+   29. If dateTimeFormat.[[Hour]] is not undefined, then
+     a. Let hcDefault be dataLocaleData.[[hourCycle]].
+     b. Let hc be dateTimeFormat.[[HourCycle]].
+     c. If hc is null, then
+        i. Set hc to hcDefault.
+     d. If hour12 is not undefined, then
+        i. If hour12 is true, then
+           1. If hcDefault is "h11" or "h23", then
+              a. Set hc to "h11".
+           2. Else,
+              a. Set hc to "h12".
+        ii. Else,
+           1. Assert: hour12 is false.
+           2. If hcDefault is "h11" or "h23", then
+              a. Set hc to "h23".
+           3. Else,
+              a. Set hc to "h24".
+     e. Set dateTimeFormat.[[HourCycle]] to hc.
+     
+locale: [en, fr, it, ja, zh, ko, ar, hi]
+---*/
+
+let locales = ["en", "fr", "it", "ja", "zh", "ko", "ar", "hi"];
+
+locales.forEach(function(locale) {
+  let hcDefault = (new Intl.DateTimeFormat(locale, {hour: "numeric"}))
+      .resolvedOptions().hourCycle;
+  if (hcDefault == "h11" || hcDefault == "h23") {
+    assert.sameValue("h11",
+        (new Intl.DateTimeFormat(locale, {hour: "numeric", hour12: true}))
+        .resolvedOptions().hourCycle);
+    assert.sameValue("h23",
+        (new Intl.DateTimeFormat(locale, {hour: "numeric", hour12: false}))
+        .resolvedOptions().hourCycle);
+  } else {
+    assert.sameValue(true, hcDefault == "h12" || hcDefault == "h24")
+    assert.sameValue("h12",
+        (new Intl.DateTimeFormat(locale, {hour: "numeric", hour12: true}))
+        .resolvedOptions().hourCycle);
+    assert.sameValue("h24",
+        (new Intl.DateTimeFormat(locale, {hour: "numeric", hour12: false}))
+        .resolvedOptions().hourCycle);
+  }
+});