Merged r17459, r17462, r17474 into 3.20 branch.

Add missing negative dictionary lookup to NonexistentHandlerFrontend

Restore intended LoadIC behavior for JSBuiltinsObject

Proper fix for the issue exposed by r17459

BUG=v8:2980
R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/99923008

git-svn-id: https://v8.googlecode.com/svn/branches/3.20@18320 ce2b1a6d-e550-0410-aec6-3dcde31c8c00