Add counters for requested/inserted/executed soft deopts

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/17498003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15253 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Handle MONOMORPIC loads where type feedback is code stub

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/17451019

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15254 ce2b1a6d-e550-0410-aec6-3dcde31c8c00