Fix issue 259.

Fix issue 259.

http://code.google.com/p/v8/issues/detail?id=259

Due to constant folding of loop conditions, it is possible to have a
try/finally with no exits from the try block (eg, an infinite loop in
the try block).  In that case the code to unlink the try handler is
dead and should not be emitted.

Review URL: http://codereview.chromium.org/39251

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1434 ce2b1a6d-e550-0410-aec6-3dcde31c8c00