Create `Date` standard constructor (#2079)

Apparently we didn't have a `Date` intrinsic constructor, we were setting the prototype of all `Date` objects to the `Object` prototype.

boa_engine/src/builtins/date/mod.rs

@@ -91,7 +91,11 @@ impl BuiltIn for Date {
     fn init(context: &mut Context) -> Option<JsValue> {
         let _timer = Profiler::global().start_event(Self::NAME, "init");
 
-        ConstructorBuilder::new(context, Self::constructor)
+        ConstructorBuilder::with_standard_constructor(
+            context,
+            Self::constructor,
+            context.intrinsics().constructors().date().clone(),
+        )
         .name(Self::NAME)
         .length(Self::LENGTH)
         .method(getter_method!(get_date), "getDate", 0)
@@ -337,7 +341,7 @@ impl Date {
             Ok(Self::make_date_string())
         } else {
             let prototype =
-                get_prototype_from_constructor(new_target, StandardConstructors::object, context)?;
+                get_prototype_from_constructor(new_target, StandardConstructors::date, context)?;
             Ok(if args.is_empty() {
                 Self::make_date_now(prototype)
             } else if args.len() == 1 {

boa_engine/src/context/intrinsics.rs

@@ -74,6 +74,7 @@ impl StandardConstructor {
 pub struct StandardConstructors {
     object: StandardConstructor,
     proxy: StandardConstructor,
+    date: StandardConstructor,
     function: StandardConstructor,
     generator: StandardConstructor,
     generator_function: StandardConstructor,
@@ -116,6 +117,7 @@ impl Default for StandardConstructors {
         let result = Self {
             object: StandardConstructor::default(),
             proxy: StandardConstructor::default(),
+            date: StandardConstructor::default(),
             function: StandardConstructor::default(),
             generator: StandardConstructor::default(),
             generator_function: StandardConstructor::default(),
@@ -191,6 +193,11 @@ impl StandardConstructors {
         &self.proxy
     }
 
+    #[inline]
+    pub fn date(&self) -> &StandardConstructor {
+        &self.date
+    }
+
     #[inline]
     pub fn function(&self) -> &StandardConstructor {
         &self.function