Temporal: Update tests to use internal slot in TimeZone and Calendar.id

In https://github.com/tc39/proposal-temporal/pull/2411, to be proposed for
consensus in TC39 in December, the .id getter of TimeZone and Calendar
should no longer call toString().

test/built-ins/Temporal/TimeZone/prototype/id/custom-timezone.js

@@ -3,17 +3,13 @@
 
 /*---
 esid: sec-get-temporal.timezone.prototype.id
-description: Getter calls toString() and returns its value
+description: Getter does not call toString(), returns the ID from internal slot
 includes: [compareArray.js, temporalHelpers.js]
 features: [Temporal]
 ---*/
 
 const actual = [];
-const expected = [
+const expected = [];
-  "get [Symbol.toPrimitive]",
-  "get toString",
-  "call timeZone.toString",
-];
 
 const timeZone = new Temporal.TimeZone("UTC");
 TemporalHelpers.observeProperty(actual, timeZone, Symbol.toPrimitive, undefined);
@@ -24,4 +20,4 @@ TemporalHelpers.observeProperty(actual, timeZone, "toString", function () {
 
 const result = timeZone.id;
 assert.compareArray(actual, expected);
-assert.sameValue(result, "time zone");
+assert.sameValue(result, "UTC");

test/built-ins/Temporal/TimeZone/prototype/id/no-toString.js

@@ -1,25 +0,0 @@
-// Copyright (C) 2020 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-get-temporal.timezone.prototype.id
-description: TypeError thrown when toString property not present
-includes: [compareArray.js]
-features: [Temporal]
----*/
-
-const actual = [];
-const expected = [
-  "get timeZone.toString",
-];
-
-const timeZone = new Temporal.TimeZone("UTC");
-Object.defineProperty(timeZone, "toString", {
-  get() {
-    actual.push("get timeZone.toString");
-    return undefined;
-  },
-});
-
-assert.throws(TypeError, () => timeZone.id);
-assert.compareArray(actual, expected);

test/staging/Temporal/UserCalendar/old/trivial-subclass.js

@@ -11,6 +11,9 @@ class TwoBasedCalendar extends Temporal.Calendar {
   constructor() {
     super("iso8601");
   }
+  get id() {
+    return "two-based";
+  }
   toString() {
     return "two-based";
   }

test/staging/Temporal/UserTimezone/old/subminute-offset.js

@@ -11,6 +11,9 @@ class SubminuteTimeZone extends Temporal.TimeZone {
   constructor() {
     super("-00:00:01.111111111");
   }
+  get id() {
+    return "Custom/Subminute";
+  }
   toString() {
     return "Custom/Subminute";
   }

test/staging/Temporal/UserTimezone/old/trivial-subclass.js

@@ -11,6 +11,9 @@ class CustomUTCSubclass extends Temporal.TimeZone {
   constructor() {
     super("UTC");
   }
+  get id() {
+    return "Etc/Custom/UTC_Subclass";
+  }
   toString() {
     return "Etc/Custom/UTC_Subclass";
   }