Fast-forward version number on bleeding_edge to 3.25.0

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/170843008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19467 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix zone_allocator to support comparison

R=danno@chromium.org

Review URL: https://codereview.chromium.org/171713004

Patch from Daniel Clifford <danno@chromium.org>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19468 ce2b1a6d-e550-0410-aec6-3dcde31c8c00