Temporal: Add toZonedDateTime tests.

test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/calendar.js

@@ -0,0 +1,19 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.tozoneddatetime
+description: Calendar of the receiver is used
+features: [Temporal]
+---*/
+
+const calendar = new Temporal.Calendar("iso8601");
+const timeCalendar = { toString() { return "iso8601"; } };
+const plainDate = new Temporal.PlainDate(2000, 5, 2, calendar);
+const result = plainDate.toZonedDateTime({
+  timeZone: "UTC",
+  plainTime: { hour: 12, minute: 30, calendar: timeCalendar },
+});
+assert.sameValue(result.epochNanoseconds, 957270600_000_000_000n);
+assert.sameValue(result.timeZone.toString(), "UTC");
+assert.sameValue(result.calendar, calendar);

test/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/timezone-getpossibleinstantsfor.js

@@ -0,0 +1,28 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.tozoneddatetime
+description: Calendar of the receiver is used
+features: [Temporal]
+---*/
+
+const calendar = new Temporal.Calendar("iso8601");
+class CustomTimeZone extends Temporal.TimeZone {
+  constructor() {
+    super("UTC");
+  }
+  getPossibleInstantsFor(plainDateTime) {
+    assert.sameValue(plainDateTime.calendar, calendar);
+    return [new Temporal.Instant(987654321_000_000_000n)];
+  }
+}
+const timeZone = new CustomTimeZone();
+const plainDate = new Temporal.PlainDate(2000, 5, 2, calendar);
+const result = plainDate.toZonedDateTime({
+  timeZone,
+  plainTime: { hour: 12, minute: 30 },
+});
+assert.sameValue(result.epochNanoseconds, 987654321_000_000_000n);
+assert.sameValue(result.timeZone, timeZone);
+assert.sameValue(result.calendar, calendar);