Add index check in DoAccessArgumentsAt.

BUG=355523
LOG=N
TEST=mjsunit/regress/regress-355523
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/210053003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20245 ce2b1a6d-e550-0410-aec6-3dcde31c8c00