Move i18n extension's date-format C++ code to runtime

src/extensions/i18n/date-format.js

Index: src/extensions/i18n/date-format.js
diff --git a/src/extensions/i18n/date-format.js b/src/extensions/i18n/date-format.js
index 04e7a7c7b9d34e50c4ec34bf2ec1e3966534c0b6..b1d28e535cd0010a2b523df8c4cb54da631c20c4 100644
--- a/src/extensions/i18n/date-format.js
+++ b/src/extensions/i18n/date-format.js
@@ -235,7 +235,6 @@ function toDateTimeOptions(options, required, defaults) {
  * Useful for subclassing.
  */
 function initializeDateTimeFormat(dateFormat, locales, options) {
-  native function NativeJSCreateDateTimeFormat();
 
   if (dateFormat.hasOwnProperty('__initializedIntlObject')) {
     throw new TypeError('Trying to re-initialize DateTimeFormat object.');
@@ -292,7 +291,7 @@ function initializeDateTimeFormat(dateFormat, locales, options) {
     year: {writable: true}
   });
 
-  var formatter = NativeJSCreateDateTimeFormat(
+  var formatter = %CreateDateTimeFormat(
     requestedLocale, {skeleton: ldmlString, timeZone: tz}, resolved);
 
   if (tz !== undefined && tz !== resolved.timeZone) {
@@ -409,8 +408,6 @@ function initializeDateTimeFormat(dateFormat, locales, options) {
  * DateTimeFormat.
  */
 function formatDate(formatter, dateValue) {
-  native function NativeJSInternalDateFormat();
-
   var dateMs;
   if (dateValue === undefined) {
     dateMs = Date.now();
@@ -422,7 +419,7 @@ function formatDate(formatter, dateValue) {
     throw new RangeError('Provided date is not in valid range.');
   }
 
-  return NativeJSInternalDateFormat(formatter.formatter, new Date(dateMs));
+  return %InternalDateFormat(formatter.formatter, new Date(dateMs));
 }
 
 
@@ -433,8 +430,7 @@ function formatDate(formatter, dateValue) {
  * Returns undefined if date string cannot be parsed.
  */
 function parseDate(formatter, value) {
-  native function NativeJSInternalDateParse();
-  return NativeJSInternalDateParse(formatter.formatter, String(value));
+  return %InternalDateParse(formatter.formatter, String(value));
 }