v8: backport no handle zapping for release builds

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

deps/v8/build/features.gypi

@@ -115,7 +115,7 @@
       'Release': {
         'variables': {
           'v8_enable_extra_checks%': 0,
-          'v8_enable_handle_zapping%': 1,
+          'v8_enable_handle_zapping%': 0,
         },
         'conditions': [
           ['v8_enable_extra_checks==1', {