Promise.join has an unexpected api

[eonarheim]

Right now Promise.join takes a rest parameter of promises, but it cannot take a simple array of promises.

public static join<T>(...promises: Promise<T>[]) {

Compiles to

 Promise.join = function () {
      var promises = [];
      for (var _i = 0; _i < arguments.length; _i++) {
           promises[_i - 0] = arguments[_i];
      }

This makes it impossible to pass just a simple array. Perhaps changing this altogether or providing an overload.

[kamranayub]

An overload seems reasonable; provides both use cases.