(cl-block, cl-return-from): Fix bug#75498

(cl-block, cl-return-from): Fix bug#75498

* lisp/emacs-lisp/cl-macs.el (cl-block, cl-return-from):
Change encoding so it obeys variable coping (i.e. lexical scoping when
`lexical-binding` is non-nil).
(cl--block-wrapper, cl--block-throw): Adjust accordingly.

* test/lisp/emacs-lisp/cl-macs-tests.el
(cl-macs--test-cl-block-lexbind-bug-75498): New test.

(cherry picked from commit dace7fa2ab468aeeca664541490eb9f291427a63)