Silence byte-compiler in some tests

* test/lisp/dired-tests.el:
* test/lisp/emacs-lisp/cl-macs-tests.el:
* test/lisp/emacs-lisp/derived-tests.el:
* test/lisp/emacs-lisp/eieio-tests/eieio-tests.el:
* test/lisp/emacs-lisp/generator-tests.el:
* test/lisp/emacs-lisp/lisp-tests.el:
* test/lisp/emacs-lisp/seq-tests.el (test-seq-let)
(test-seq-setq):
* test/lisp/emacs-lisp/subr-x-tests.el (subr-x-test-if-let*-false)
(subr-x-test-if-let*-and-laziness-is-preserved)
(subr-x-test-when-let*-false)
(subr-x-test-when-let*-and-laziness-is-preserved):
* test/lisp/emacs-lisp/timer-tests.el
(timer-tests-debug-timer-check):
* test/lisp/format-spec-tests.el (format-spec-do-flags-truncate)
(format-spec-do-flags-pad):
* test/lisp/ls-lisp-tests.el (ls-lisp-test-bug27762):
* test/lisp/obsolete/cl-tests.el (labels-function-quoting):
* test/lisp/progmodes/elisp-mode-tests.el:
* test/lisp/replace-tests.el (replace-regexp-bug45973):
* test/lisp/ses-tests.el:
* test/lisp/subr-tests.el:
* test/lisp/tar-mode-tests.el (tar-mode-test-tar-grind-file-mode):
* test/src/data-tests.el (data-tests--set-default-per-buffer):
* test/src/search-tests.el
(test-replace-match-modification-hooks): Silence byte-compiler.

test/lisp/emacs-lisp/lisp-tests.el

@@ -213,6 +213,7 @@
     (should-error (forward-sexp)))) ;; FIXME: Shouldn't be an error.
 
 ;; Test some core Elisp rules.
+(defvar c-e-x)
 (ert-deftest core-elisp-tests-1-defvar-in-let ()
   "Test some core Elisp rules."
   (with-temp-buffer