As described in the issue 1532, this may lead to building a 32-bit version over
existing x64-bit. It's better delegate to delegate this task to an user.

R=vitalyr@chromium.org
BUG=1532

Review URL: http://codereview.chromium.org/7309012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8530 ce2b1a6d-e550-0410-aec6-3dcde31c8c00