Fix typed lowering of JSToBoolean on number inputs.

R=titzer@chromium.org
TEST=cctest/test-js-typed-lowering/JSToBoolean_replacement

Review URL: https://codereview.chromium.org/533103002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23642 ce2b1a6d-e550-0410-aec6-3dcde31c8c00