Uniformly and exhaustively test the generic aspects of the static- and
instance Promise methods, including:

- function `length` properties
- function `name` properties
- method property descriptors

This test's description concerns the behavior of `Promise.all` when the
IteratorStep abstract operation fails due to an abrupt completion
returned by the iterator's `next` method. The test body did not actually
assert that functionality.

Update the test body to correctly define the requisite iterator and
assert that the specific error created is the one thrown from the
invocation of `Promise.all`

Promise methods should not be enumerable, per https://people.mozilla.org/~jorendorff/es6-draft.html#table-4