Disable handle zapping for release builds on 3.26

BUG=318206
LOG=y
R=danno@chromium.org

Review URL: https://codereview.chromium.org/295673002

git-svn-id: https://v8.googlecode.com/svn/branches/3.26@21367 ce2b1a6d-e550-0410-aec6-3dcde31c8c00