[Intl] Remove extra set_intl_date_time_format_function()

Bug: v8:5751
Change-Id: I51c76880059ab5ce62032777d01d7e44849e874a
Reviewed-on: https://chromium-review.googlesource.com/c/1275808Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56668}

src/bootstrapper.cc

@@ -2918,9 +2918,6 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
           isolate_, date_time_format_constructor,
           Context::INTL_DATE_TIME_FORMAT_FUNCTION_INDEX);
 
-      native_context()->set_intl_date_time_format_function(
-          *date_time_format_constructor);
-
       SimpleInstallFunction(
           isolate(), date_time_format_constructor, "supportedLocalesOf",
           Builtins::kDateTimeFormatSupportedLocalesOf, 1, false);