The number of different detail strings has been reduced a bit without
any loss of information. Furthermore, DoubleToI is a bit more
informative now. Tiny reason fixes.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/591393002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24146 ce2b1a6d-e550-0410-aec6-3dcde31c8c00