es6-promise - add .polyfill() method

es6-promise/es6-promise.d.ts

@@ -68,6 +68,7 @@ declare module 'es6-promise' {
 	var foo: typeof Promise; // Temp variable to reference Promise in local context
 	module rsvp {
 		export var Promise: typeof foo;
+		export function polyfill();
 	}
 	export = rsvp;
 }