This exposed an internal implementation detail, which could be handled
differently.

BUG=v8:3274
LOG=y
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/285643008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21297 ce2b1a6d-e550-0410-aec6-3dcde31c8c00