Use lexical-binding in more tests

* test/lib-src/emacsclient-tests.el:
* test/lisp/emacs-lisp/hierarchy-tests.el:
* test/lisp/eshell/eshell-tests.el:
* test/lisp/gnus/gnus-util-tests.el:
* test/lisp/progmodes/js-tests.el:
* test/lisp/textmodes/bibtex-tests.el:
* test/src/editfns-tests.el:
* test/src/fns-tests.el: Use lexical-binding.

* test/lisp/emacs-lisp/hierarchy-tests.el
(hierarchy-leafs-includes-lonely-roots):
* test/src/editfns-tests.el (transpose-test-get-byte-positions):
* test/src/fns-tests.el (fns-tests-func-arity):
Adjust for lexical-binding.

test/src/editfns-tests.el

@@ -1,4 +1,4 @@
-;;; editfns-tests.el -- tests for editfns.c
+;;; editfns-tests.el -- tests for editfns.c  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2016-2020 Free Software Foundation, Inc.
 
@@ -124,8 +124,8 @@
   "Validate character position to byte position translation."
   (let ((bytes '()))
     (dotimes (pos len)
-      (setq bytes (add-to-list 'bytes (position-bytes (1+ pos)) t)))
-    bytes))
+      (push (position-bytes (1+ pos)) bytes))
+    (nreverse bytes)))
 
 (ert-deftest transpose-ascii-regions-test ()
   (with-temp-buffer

test/src/fns-tests.el

@@ -1,4 +1,4 @@
-;;; fns-tests.el --- tests for src/fns.c
+;;; fns-tests.el --- tests for src/fns.c  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2014-2020 Free Software Foundation, Inc.
 
@@ -229,8 +229,8 @@
   (require 'info)
   (should (equal (func-arity 'Info-goto-node) '(1 . 3)))
   (should (equal (func-arity (lambda (&rest x))) '(0 . many)))
-  (should (equal (func-arity (eval (lambda (x &optional y)) nil)) '(1 . 2)))
-  (should (equal (func-arity (eval (lambda (x &optional y)) t)) '(1 . 2)))
+  (should (equal (func-arity (eval '(lambda (x &optional y)) nil)) '(1 . 2)))
+  (should (equal (func-arity (eval '(lambda (x &optional y)) t)) '(1 . 2)))
   (should (equal (func-arity 'let) '(1 . unevalled))))
 
 (defun fns-tests--string-repeat (s o)