Fast literals: fixed initialization of non-copied in-object property fields

BUG=chromium:245424
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/16190008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14906 ce2b1a6d-e550-0410-aec6-3dcde31c8c00