Further improve deopt reason output.

* Make the detailed deopt reason mandatory on x64, other platforms
  will follow in separate CLs.

* Extracted and improved jump table entry sharing logic: When
  --trace-deopt is on, we get separate entries for different deopt
  reasons. This enables us to distinguish the several reasons single
  instructions can have.

* Don't emit superfluous jump table comments: The bailout ID is still
  visible, and the jump table entry number is not interesting (but
  easy to determine if really needed).

* Unify the internal name of the jump table member across platforms.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/595513002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24123 ce2b1a6d-e550-0410-aec6-3dcde31c8c00