was always falling through to the runtime. Re-examined both load and
store ICs and verified they are now in sync with the 32-bit port.

Ran tests and benchmarks.

Review URL: http://codereview.chromium.org/385020

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3286 ce2b1a6d-e550-0410-aec6-3dcde31c8c00