Revert "FastElementsAccessor::SetLengthWithoutNormalize() handlified."

This reverts commit r20214 for breaking debug tests on various platforms.

R=vogelheim@chromium.org

Review URL: https://codereview.chromium.org/208313015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20216 ce2b1a6d-e550-0410-aec6-3dcde31c8c00