Fix issue 1692.

BUG=v8:1692
TEST=mjsunit/regress/regress-1692

Review URL: http://codereview.chromium.org/8113001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9503 ce2b1a6d-e550-0410-aec6-3dcde31c8c00