Merged r17703 into trunk branch.

Slight change to Math.sin approximation.

R=yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/71473004

git-svn-id: https://v8.googlecode.com/svn/trunk@17706 ce2b1a6d-e550-0410-aec6-3dcde31c8c00