Since we add more type (StringType, PrimitiveType) the name
NumberInfo does not make sense anymore.

Review URL: http://codereview.chromium.org/1207006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4268 ce2b1a6d-e550-0410-aec6-3dcde31c8c00