Add a proper way to pass the number of processors to V8

BUG=321060
LOG=n
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/73463004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17874 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix debugger wrt concurrent recompilation flag.

R=svenpanne@chromium.org
BUG=

Review URL: https://codereview.chromium.org/76293003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17875 ce2b1a6d-e550-0410-aec6-3dcde31c8c00