Flush instruction cache for deserialized code objects.

This fixes the flaky crashes on ARM when running preparser test suite in
optdebug mode.

R=svenpanne@chromium.org

Review URL: https://chromiumcodereview.appspot.com/107543003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18314 ce2b1a6d-e550-0410-aec6-3dcde31c8c00