of having a list of virtual frame pointers in the jump
target we have one virtual frame, which is the frame that
all have to merge to to branch to that frame.  The virtual
frame in the JumpTarget is inside the JumpTarget, rather than
being an allocated object that is pointed to.  Unfortunately
this means that the JumpTarget class has to be able to see
the size of a VirtualFrame object to compile, which in turn
lead to a major reorganization of related .h files.  The
actual change of functionality in this change is intended
to be minimal (we now assert that the virtual frames match
when using JumpTarget instead of just assuming that they do).
Review URL: http://codereview.chromium.org/1961004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4631 ce2b1a6d-e550-0410-aec6-3dcde31c8c00