BUG=
TEST=--smi-only-arrays should be perf-neutral to allocating big arrays in a tight loop.

Review URL: https://chromiumcodereview.appspot.com/9356002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10711 ce2b1a6d-e550-0410-aec6-3dcde31c8c00