Merged r17459, r17462, r17474 into 3.21 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=verwaest@chromium.org

Review URL: https://codereview.chromium.org/66723020

git-svn-id: https://v8.googlecode.com/svn/branches/3.21@17650 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merged r17441 into 3.21 branch.

Fix uint32-to-smi conversion in Lithium

BUG=chromium:309623
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/66783007

git-svn-id: https://v8.googlecode.com/svn/branches/3.21@17652 ce2b1a6d-e550-0410-aec6-3dcde31c8c00