Avoid warnings about lexbind cookies where they aren't needed

* lisp/emacs-lisp/warnings.el (warning-inhibit-types): New variable.
(display-warning): If TYPE matches 'warning-inhibit-types', don't
display the warning, even if it's emitted during startup.
* lisp/startup.el (normal-top-level):
* lisp/savehist.el (savehist-mode):
* lisp/url/url-cookie.el (url-cookie-parse-file):
* lisp/recentf.el (recentf-load-list):
* lisp/abbrev.el (read-abbrev-file): Bind 'warning-inhibit-types'
to avoid warning about missing lexbind cookie when loading files
that Emacs itself generates.

lisp/abbrev.el

@@ -225,7 +225,8 @@ about loading the abbrevs."
    (list
     (read-file-name (format-prompt "Read abbrev file" abbrev-file-name)
 		    nil abbrev-file-name t)))
-  (load (or file abbrev-file-name) nil quietly)
+  (let ((warning-inhibit-types '((files missing-lexbind-cookie))))
+    (load (or file abbrev-file-name) nil quietly))
   (setq abbrevs-changed nil))
 
 (defun quietly-read-abbrev-file (&optional file)

lisp/emacs-lisp/warnings.el

@@ -176,6 +176,9 @@ also call that function before the next warning.")
   "Format for displaying the warning type in the warning message.
 The result of formatting the type this way gets included in the
 message under the control of the string in `warning-levels'.")
+;;;###autoload
+(defvar warning-inhibit-types nil
+  "Like `warning-suppress-log-types', but intended for programs to let-bind.")
 
 (defun warning-numeric-level (level)
   "Return a numeric measure of the warning severity level LEVEL."
@@ -277,9 +280,10 @@ disable automatic display of the warning or disable the warning
 entirely by setting `warning-suppress-types' or
 `warning-suppress-log-types' on their behalf."
   (if (not (or after-init-time noninteractive (daemonp)))
-      ;; Ensure warnings that happen early in the startup sequence
-      ;; are visible when startup completes (bug#20792).
-      (delay-warning type message level buffer-name)
+      (or (warning-suppress-p type warning-inhibit-types)
+          ;; Ensure warnings that happen early in the startup sequence
+          ;; are visible when startup completes (bug#20792).
+          (delay-warning type message level buffer-name))
     (unless level
       (setq level :warning))
     (unless buffer-name
@@ -290,6 +294,7 @@ entirely by setting `warning-suppress-types' or
         (setq level new)))
     (or (< (warning-numeric-level level)
 	   (warning-numeric-level warning-minimum-log-level))
+        (warning-suppress-p type warning-inhibit-types)
 	(warning-suppress-p type warning-suppress-log-types)
 	(let* ((typename (if (consp type) (car type) type))
 	       (old (get-buffer buffer-name))

lisp/recentf.el

@@ -1362,7 +1362,8 @@ empty `file-name-history' with the recent list."
         ;; We do not want Tramp asking for passwords.
         (non-essential t))
     (when (file-readable-p file)
-      (load-file file)
+      (let ((warning-inhibit-types '((files missing-lexbind-cookie))))
+        (load-file file))
       (and recentf-initialize-file-name-history
            (not file-name-history)
            (setq file-name-history (mapcar #'abbreviate-file-name

lisp/savehist.el

@@ -205,7 +205,9 @@ histories, which is probably undesirable."
 	    ;; coding cookie to convey that information.  That way, if
 	    ;; the user changes the value of savehist-coding-system,
 	    ;; we can still correctly load the old file.
-	    (load savehist-file nil (not (called-interactively-p 'interactive)))
+            (let ((warning-inhibit-types '((files missing-lexbind-cookie))))
+	      (load savehist-file nil
+                    (not (called-interactively-p 'interactive))))
 	    (setq savehist-loaded t))
 	(error
 	 ;; Don't install the mode if reading failed.  Doing so would

lisp/startup.el

@@ -620,13 +620,15 @@ It is the default value of the variable `top-level'."
           dir)
       (while tail
         (setq dir (car tail))
-        (let ((default-directory dir))
+        (let ((default-directory dir)
+              (warning-inhibit-types '((files missing-lexbind-cookie))))
           (load (expand-file-name "subdirs.el") t t t))
         ;; Do not scan standard directories that won't contain a leim-list.el.
         ;; https://lists.gnu.org/r/emacs-devel/2009-10/msg00502.html
         ;; (Except the preloaded one in lisp/leim.)
         (or (string-prefix-p lispdir dir)
-            (let ((default-directory dir))
+            (let ((default-directory dir)
+                  (warning-inhibit-types '((files missing-lexbind-cookie))))
               (load (expand-file-name "leim-list.el") t t t)))
         ;; We don't use a dolist loop and we put this "setq-cdr" command at
         ;; the end, because the subdirs.el files may add elements to the end

lisp/url/url-cookie.el

@@ -73,7 +73,8 @@ telling Microsoft that."
 (defun url-cookie-parse-file (&optional fname)
   "Load FNAME, default `url-cookie-file'."
   ;; It's completely normal for the cookies file not to exist yet.
-  (load (or fname url-cookie-file) t t))
+  (let ((warning-inhibit-types '((files missing-lexbind-cookie))))
+    (load (or fname url-cookie-file) t t)))
 
 (defun url-cookie-parse-file-netscape (filename &optional long-session)
   "Load cookies from FILENAME in Netscape/Mozilla format.