This is nice when looking at hydrogen graphs, to see the real key offset.

R=mmassi@chromium.org
BUG=

Review URL: https://codereview.chromium.org/11348176

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13032 ce2b1a6d-e550-0410-aec6-3dcde31c8c00