Update Array Iterator to use numeric indexes

Update Array Iterator to use numeric indexes

At the last face-to-face meeting it was decided that we should use
numeric indexes for the Array Iterator values.

https://github.com/rwldrn/tc39-notes/blob/master/es6/2013-07/july-24.md#514-keys-entries-return-numbers-for-array-index-properties

BUG=v8:2818
R=dslomov@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16072

[Michael Starzinger, 2013-08-01 08:11:24]

I'll leave this one to Andreas. He will be back on Monday.

[arv (Not doing code reviews), 2013-08-01 13:50:49]

Adding Dmitry who was there at the F2F

[rossberg, 2013-08-06 08:29:33]

Looks fine to me, but I'll let Dmitry decide, since I'm still in catch-up mode
re the latest meeting.

[Dmitry Lomov (no reviews), 2013-08-06 11:34:42]

lgtm

[Dmitry Lomov (no reviews), 2013-08-06 13:03:29]

On 2013/08/06 11:34:42, Dmitry Lomov (chromium) wrote:
> lgtm

(I'll land)

[Dmitry Lomov (no reviews), 2013-08-06 13:10:12]

Committed patchset #1 manually as r16072 (presubmit successful).