Linux perf support update.

Linux perf tool support update + refactoring.

This adds timestamps to allow profiling with code space reuse. Also a couple of updates to reflect the changes in the JIT perf interface + a move of the perf-related stuff into separate files.

Unfortunately, the change only works with the latest patch  to the perf tool from a Linux perf tool contributor (Stephane Eranian).

BUG=
R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22098

[Jarin, 2014-06-30 12:49:20]

Could you have a look?

[Yang, 2014-06-30 12:59:01]

On 2014/06/30 12:49:20, jarin wrote:
> Could you have a look?

lgtm.

[Jarin, 2014-06-30 14:36:43]

Committed patchset #6 manually as r22098 (presubmit successful).

[weiliang.lin2, 2014-07-04 02:56:01]

Great support!
Could you please share where to get the the latest patch to the perf tool from a
Linux perf tool contributor (Stephane Eranian)?

Thanks
-Weiliang

[Jarin, 2014-07-08 08:03:15]

On 2014/07/04 02:56:01, weiliang.lin2 wrote:
> Great support!
> Could you please share where to get the the latest patch to the perf tool from
a
> Linux perf tool contributor (Stephane Eranian)?
> 
> Thanks
> -Weiliang

Stephane says the patch is only for internal testing, but he is hoping to
release the patch publicly by the end of the month.

[Weiliang, 2014-07-08 09:22:21]

On 2014/07/08 08:03:15, jarin wrote:
> On 2014/07/04 02:56:01, weiliang.lin2 wrote:
> > Great support!
> > Could you please share where to get the the latest patch to the perf tool
from
> a
> > Linux perf tool contributor (Stephane Eranian)?
> > 
> > Thanks
> > -Weiliang
> 
> Stephane says the patch is only for internal testing, but he is hoping to
> release the patch publicly by the end of the month.

Thanks for the information