Infer the range of Math.abs

R=jkummerow@chromium.org, svenpanne@chromium.org

Review URL: https://chromiumcodereview.appspot.com/16268009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14996 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Don't ignore the actual input representation in UnaryMathOperations

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/16035014

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14997 ce2b1a6d-e550-0410-aec6-3dcde31c8c00