Require smi for keyed store to smi.

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15884002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14779 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Simplifying GC heuristics, deleted old generation allocation limit.

BUG=

Review URL: https://codereview.chromium.org/14700006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14780 ce2b1a6d-e550-0410-aec6-3dcde31c8c00