message: [Performance] Use the Date.toISOString() native function if it exists
diff: @@ -13,6 +13,7 @@ const strAttachEvent = "attachEvent";
  const strAddEventHelper = "addEventListener";
  const strDetachEvent = "detachEvent";
  const strRemoveEventListener = "removeEventListener";
  +const strToISOString = "toISOString";
  const _objDefineProperty = ObjDefineProperty;
  const _objFreeze = ObjClass["freeze"];
  @@ -271,6 +272,12 @@ export function isSymbol(value: any): boolean {
  * Convert a date to I.S.O. format in IE8
  */
  export function toISOString(date: Date) {
  + if (date) {
  + if (date[strToISOString]) {
  + // For Performance try and use the native instance, using string lookup of the function to easily pass the ES3 build checks and minification
  + return date[strToISOString]();
  + }
  +
  if (isDate(date)) {
  const pad = (num: number) => {
  let r = String(num);
  @@ -291,6 +298,7 @@ export function toISOString(date: Date) {
  + "Z";
  }
  }
  +}
  /**
  * Performs the specified action for each element in an array. This helper exists to avoid adding a polyfil for older browsers
  