Handlify JSObject::DefineAccessor method.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/18497003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15458 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix default type feedback returned from the oracle

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/18465003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00