Add tree control feature to auto-roll script.

This CL enables the auto-roll script to close and reopen the tree when pushing.

Modifies an auto-roll test so that the push-to-trunk part is executed in order to test the new tree control feature.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/130403006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18622 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Revert of Make it possible to compile d8 for the host toolset as well (https://codereview.chromium.org/139493002/)

Reason for revert:
still doesn't work on arm

Original issue's description:
> Make it possible to compile d8 for the host toolset as well
>
> 2nd attempt. Use a different output path for the host d8.
>
> BUG=v8:1775
> R=machenbach@chromium.org
> LOG=n
>
> Committed: https://code.google.com/p/v8/source/detail?r=18621

R=machenbach@chromium.org
TBR=machenbach@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=v8:1775

Review URL: https://codereview.chromium.org/139523003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18623 ce2b1a6d-e550-0410-aec6-3dcde31c8c00