- Prevent a clipping of values when converting a double to an unsigned int
  for use as the random generator's seed value.
Review URL: http://codereview.chromium.org/1887

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@246 ce2b1a6d-e550-0410-aec6-3dcde31c8c00