Implement correct OS and CC detection.

Implement correct OS and CC detection.

R=svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15923

[Benedikt Meurer, 2013-07-28 17:10:57]

First round

[Sven Panne, 2013-07-29 07:54:08]

LGTM if the changes to atomicops.h are reverted: That file is a copy from
Chrome's base/atomicops.h IIRC, and those files should be in sync.

[Benedikt Meurer, 2013-07-29 07:57:48]

On 2013/07/29 07:54:08, Sven Panne wrote:
> LGTM if the changes to atomicops.h are reverted: That file is a copy from
> Chrome's base/atomicops.h IIRC, and those files should be in sync.

Maybe they were in sync at some point in the past, but it looks like they
haven't been for quite some time now. And I don't think there are ways to keep
them in sync properly.

[Benedikt Meurer, 2013-07-29 09:18:58]

Reverted changes to atomicops*.h

[Benedikt Meurer, 2013-07-29 09:19:22]

Committed patchset #4 manually as r15923 (presubmit successful).

[Sven Panne, 2013-07-29 09:25:16]

Although this is already submitted: I think that it would be good to sync
src/atomicops* with chromium/src/base/ again, keeping the diff at a minimum.
Jochen/Danno: WDYT?

[Benedikt Meurer, 2013-07-29 09:26:54]

On 2013/07/29 09:25:16, Sven Panne wrote:
> Although this is already submitted: I think that it would be good to sync
> src/atomicops* with chromium/src/base/ again, keeping the diff at a minimum.
> Jochen/Danno: WDYT?

Chromium has a different set of #define's here. But as long as everything else
is untouched, we can just copy over the chromium files and fixup the #ifdef's.