Condense flag definitions a bit.

This makes it easy to spot the default value of a flag when grepping the
code as the default value appears on the same line as the name now.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/35213002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17326 ce2b1a6d-e550-0410-aec6-3dcde31c8c00