This initial implementation generates only KeyedLoadICs using the new Hydrogen stub infrastructure.

Committed: https://code.google.com/p/v8/source/detail?r=13105

Committed: https://code.google.com/p/v8/source/detail?r=13117

Review URL: https://codereview.chromium.org/10701054

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13140 ce2b1a6d-e550-0410-aec6-3dcde31c8c00