Eliminate unused function KeyedStoreIC::GenerateExtendStorage, and unused parameter from StubCompiler::GenerateStoreField.
Review URL: http://codereview.chromium.org/575022

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3824 ce2b1a6d-e550-0410-aec6-3dcde31c8c00