Fix closure-conversion of shadowed captured lambda-lifted vars

Fix closure-conversion of shadowed captured lambda-lifted vars

Lambda-lifted variables (ones passed explicitly to lambda-lifted
functions) that are also captured in an outer closure and shadowed
were renamed incorrectly (bug#51982).

Reported by Paul Pogonyshev.

* lisp/emacs-lisp/cconv.el (cconv--lifted-arg): New.
(cconv-convert): Provide correct definiens for the closed-over
variable.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--test-cases):
* test/lisp/emacs-lisp/cconv-tests.el (cconv-tests--intern-all)
(cconv-closure-convert-remap-var): Add tests.