Make Map.set() and Set.add() chainable

Make Map.set() and Set.add() chainable

From the Harmony draft:

https://people.mozilla.org/~jorendorff/es6-draft.html#sec-map.prototype.set
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-weakmap.prototype.set
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-set.prototype.add
https://people.mozilla.org/~jorendorff/es6-draft.html#sec-weakset.prototype.add

BUG=v8:3410
R=arv@chromium.org, rossberg@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22111

[caitp (gmail), 2014-06-28 23:54:47]

Just re-opening this against bleeding_edge

[arv (Not doing code reviews), 2014-06-30 18:23:05]

LGTM

Andreas, Caitlin has signed the CLA so this should be good to merge.

[caitp (gmail), 2014-06-30 18:32:29]

I think it's merge-able, but there's 3 failing tests in the intl suite that look
unrelated to the patch. I'm not sure if that's really my fault or no.

It would be super helpful to run some tests and see for sure if I broke
something or not. One of these days I'll be able to run try jobs myself, but for
now it looks like I need to ask for help with that =)

[arv (Not doing code reviews), 2014-06-30 18:43:11]

On 2014/06/30 at 18:32:29, caitpotter88 wrote:
> I think it's merge-able, but there's 3 failing tests in the intl suite that
look unrelated to the patch. I'm not sure if that's really my fault or no.
> 
> It would be super helpful to run some tests and see for sure if I broke
something or not. One of these days I'll be able to run try jobs myself, but for
now it looks like I need to ask for help with that =)

I started a try job.

[caitp (gmail), 2014-07-01 00:45:11]

It looks like the layout bot failures aren't unique to this CL, so unless
someone says otherwise I'll submit this for the CQ tomorrow.

[rossberg, 2014-07-01 09:46:25]

lgtm

[rossberg, 2014-07-01 09:49:43]

Committed patchset #1 manually as r22111 (tree was closed).