Sunspider verifies floating point results to the last bit, so this is to
make sure that we return the expected result.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/71123003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17685 ce2b1a6d-e550-0410-aec6-3dcde31c8c00