Temporary workaround for GC stress builder.

R=hpayer@chromium.org, hpayer@google.com
TEST=cctest/test-debug/ScriptCollectedEventContext --gc-interval=500

Review URL: https://codereview.chromium.org/22987004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16216 ce2b1a6d-e550-0410-aec6-3dcde31c8c00