query-replace-regexp undo: Update next-replacement after undo

* lisp/replace.el (perform-replace):
Rename the local binding to not shadow next-replacement.
Update next-replacement after undo (Bug#37287).

* test/lisp/replace-tests.el (query-replace-undo-bug37287): Add test.
(query-replace-undo-bug37073): Tweak this test.
1 job for emacs-26 in 25 minutes and 47 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #3240
test

00:25:47