LibJS: Start implementing Temporal.ZonedDateTime

This commit adds the ZonedDateTime object itself, its constructor and
prototype (currently empty), and the CreateTemporalZonedDateTime
abstract operation.

Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimeConstructor.cpp

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/Temporal/Calendar.h>
+#include <LibJS/Runtime/Temporal/Instant.h>
+#include <LibJS/Runtime/Temporal/TimeZone.h>
+#include <LibJS/Runtime/Temporal/ZonedDateTime.h>
+#include <LibJS/Runtime/Temporal/ZonedDateTimeConstructor.h>
+
+namespace JS::Temporal {
+
+// 6.1 The Temporal.ZonedDateTime Constructor, https://tc39.es/proposal-temporal/#sec-temporal-zoneddatetime-constructor
+ZonedDateTimeConstructor::ZonedDateTimeConstructor(GlobalObject& global_object)
+    : NativeFunction(vm().names.ZonedDateTime.as_string(), *global_object.function_prototype())
+{
+}
+
+void ZonedDateTimeConstructor::initialize(GlobalObject& global_object)
+{
+    NativeFunction::initialize(global_object);
+
+    auto& vm = this->vm();
+
+    // 6.2.1 Temporal.ZonedDateTime.prototype, https://tc39.es/proposal-temporal/#sec-temporal-zoneddatetime-prototype
+    define_direct_property(vm.names.prototype, global_object.temporal_zoned_date_time_prototype(), 0);
+
+    define_direct_property(vm.names.length, Value(2), Attribute::Configurable);
+}
+
+// 6.1.1 Temporal.ZonedDateTime ( epochNanoseconds, timeZoneLike [ , calendarLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime
+Value ZonedDateTimeConstructor::call()
+{
+    auto& vm = this->vm();
+
+    // 1. If NewTarget is undefined, then
+    // a. Throw a TypeError exception.
+    vm.throw_exception<TypeError>(global_object(), ErrorType::ConstructorWithoutNew, "Temporal.ZonedDateTime");
+    return {};
+}
+
+// 6.1.1 Temporal.ZonedDateTime ( epochNanoseconds, timeZoneLike [ , calendarLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime
+Value ZonedDateTimeConstructor::construct(FunctionObject& new_target)
+{
+    auto& vm = this->vm();
+    auto& global_object = this->global_object();
+
+    // 2. Set epochNanoseconds to ? ToBigInt(epochNanoseconds).
+    auto* epoch_nanoseconds = vm.argument(0).to_bigint(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. If ! IsValidEpochNanoseconds(epochNanoseconds) is false, throw a RangeError exception.
+    if (!is_valid_epoch_nanoseconds(*epoch_nanoseconds)) {
+        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidEpochNanoseconds);
+        return {};
+    }
+
+    // 4. Let timeZone be ? ToTemporalTimeZone(timeZoneLike).
+    auto* time_zone = to_temporal_time_zone(global_object, vm.argument(1));
+    if (vm.exception())
+        return {};
+
+    // 5. Let calendar be ? ToTemporalCalendarWithISODefault(calendarLike).
+    auto* calendar = to_temporal_calendar_with_iso_default(global_object, vm.argument(2));
+    if (vm.exception())
+        return {};
+
+    // 6. Return ? CreateTemporalZonedDateTime(epochNanoseconds, timeZone, calendar, NewTarget).
+    return create_temporal_zoned_date_time(global_object, *epoch_nanoseconds, *time_zone, *calendar, &new_target);
+}
+
+}