Make UBSan happy.

This involves avoiding signed multiplication overflow, shifting too
far and overflow during negation.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/382153003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22351 ce2b1a6d-e550-0410-aec6-3dcde31c8c00