Current v8 implementation may disable optimization for a particular function or block it with help of dont_optimize flag.
The patch propagates the reason of that to the SharedFunctionInfo where cpu profiler can get it.

SharedFunctionInfo is a heap object so I extracted 8 bits from OptsCount for handling bailout reason code.

BUG=none
TEST=test-profile-generator/BailoutReason
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/23817003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16555 ce2b1a6d-e550-0410-aec6-3dcde31c8c00