BUG=None
TEST=mjsunit/external-arrays.js; updated cctest; existing unit tests

Review URL: http://codereview.chromium.org/6879009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7675 ce2b1a6d-e550-0410-aec6-3dcde31c8c00