Port r19749 (4880ed9)

Original commit message:
Fixed the flooring div bug and added a test case.

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/192743006

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19774 ce2b1a6d-e550-0410-aec6-3dcde31c8c00