Remove generation of old bytecodes for catch/unwind

Remove generation of old bytecodes for catch/unwind

* lisp/emacs-lisp/bytecomp.el (byte-compile--use-old-handlers)
(byte-compile-condition-case, byte-compile-condition-case--old):
Remove.
(byte-compile-condition-case--new):
Rename to byte-compile-condition-case.
(byte-compile-catch, byte-compile-unwind-protect):
* lisp/emacs-lisp/cconv.el (cconv-convert, cconv-analyze-form):
* lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker):
Simplify.