Update harmony Object.prototype.toString to 2/2/2015 spec

Update harmony Object.prototype.toString to 2/2/2015 spec

- Removes special handling of non-string @@toStringTag values (use builtinTag)
- Removes special handling of @@toStringTags which match [[Class]] names (remove ~ prefix)

BUG=v8:3502
R=arv@chromium.org
LOG=N

Committed: https://crrev.com/858b9b6a7e6c86464e7bb8ca87f8649ca9d1cdba
Cr-Commit-Position: refs/heads/master@{#26411}

[caitp (gmail), 2015-02-03 15:29:24]

PTAL -- pretty trivial, might be some comments still need to be removed in tests
though

[caitp (gmail), 2015-02-03 15:30:05]

On 2015/02/03 15:29:24, caitp wrote:
> PTAL -- pretty trivial, might be some comments still need to be removed in
tests
> though

I guess there's still more to do in api.cc though

[arv (Not doing code reviews), 2015-02-03 15:32:23]

LGTM

Do you want to do the .cc in a different CL?

[caitp (gmail), 2015-02-03 15:33:07]

On 2015/02/03 15:32:23, arv wrote:
> LGTM
> 
> Do you want to do the .cc in a different CL?

Sure

[caitp (gmail), 2015-02-03 15:40:10]

The CQ bit was checked by caitpotter88@gmail.com

[commit-bot: I haz the power, 2015-02-03 15:40:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/895633004/1

[caitp (gmail), 2015-02-03 15:49:54]

https://codereview.chromium.org/895633004/diff/1/test/mjsunit/es6/object-tost...
File test/mjsunit/es6/object-tostring.js (right):

https://codereview.chromium.org/895633004/diff/1/test/mjsunit/es6/object-tost...
test/mjsunit/es6/object-tostring.js:5: // Flags: --harmony-tostring
--allow-natives-syntax
hmmm, I thought I was going to use this for %_ClassOf(), but I guess I didn't
really need it... I'll remove it in the other CL

[commit-bot: I haz the power, 2015-02-03 17:45:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-03 17:45:27]

Patchset 1 (id:??) landed as
https://crrev.com/858b9b6a7e6c86464e7bb8ca87f8649ca9d1cdba
Cr-Commit-Position: refs/heads/master@{#26411}