Enable optimization of functions with generic switches.

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

Review URL: https://chromiumcodereview.appspot.com/110123002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18347 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Hydrogen: Re-use regular comparisons infrastructure for switch statements

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/111573003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@18348 ce2b1a6d-e550-0410-aec6-3dcde31c8c00