First round of JumpTarget simplification. Remove dead functions (jumps,

First round of JumpTarget simplification.  Remove dead functions (jumps,
branches, and bind with more than two arguments).  Remove unneeded
variable (the "watermark" on virtual frames).

Review URL: http://codereview.chromium.org/125045

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2153 ce2b1a6d-e550-0410-aec6-3dcde31c8c00