Implement date library functions in C++.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 4498286916238f6ea009c1a3a0ce9124eb5e6cc4..2ced9b7b85dd4754bf165f65d7e76b0ae8cafd96 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -4734,8 +4734,8 @@ double v8::Date::NumberValue() const {
   if (IsDeadCheck(isolate, "v8::Date::NumberValue()")) return 0;
   LOG_API(isolate, "Date::NumberValue");
   i::Handle<i::Object> obj = Utils::OpenHandle(this);
-  i::Handle<i::JSValue> jsvalue = i::Handle<i::JSValue>::cast(obj);
-  return jsvalue->value()->Number();
+  i::Handle<i::JSDate> jsdate = i::Handle<i::JSDate>::cast(obj);
+  return jsdate->value()->Number();
 }
 
 
@@ -4746,8 +4746,10 @@ void v8::Date::DateTimeConfigurationChangeNotification() {
   LOG_API(isolate, "Date::DateTimeConfigurationChangeNotification");
   ENTER_V8(isolate);
 
+  isolate->date_cache()->ResetDateCache();
+
   i::HandleScope scope(isolate);
-  // Get the function ResetDateCache (defined in date-delay.js).
+  // Get the function ResetDateCache (defined in date.js).
   i::Handle<i::String> func_name_str =
       isolate->factory()->LookupAsciiSymbol("ResetDateCache");
   i::MaybeObject* result =