Make buffer-local-value obsolete as a generalized variable

* lisp/electric.el (electric-indent-local-mode)
(electric-layout-local-mode, electric-quote-local-mode):
* lisp/elec-pair.el (electric-pair-local-mode): Adjust usage.
* lisp/emacs-lisp/gv.el (make-obsolete-generalized-variable): Move
since we're using it earlier in the file.
(buffer-local-value): Make obsolete as a generalized variable
since the semantics are unclear (bug#26624).

lisp/elec-pair.el

@@ -666,7 +666,8 @@ To toggle the mode in a single buffer, use `electric-pair-local-mode'."
 ;;;###autoload
 (define-minor-mode electric-pair-local-mode
   "Toggle `electric-pair-mode' only in this buffer."
-  :variable (buffer-local-value 'electric-pair-mode (current-buffer))
+  :variable ( electric-pair-mode .
+              (lambda (val) (setq-local electric-pair-mode val)))
   (cond
    ((eq electric-pair-mode (default-value 'electric-pair-mode))
     (kill-local-variable 'electric-pair-mode))

lisp/electric.el

@@ -340,7 +340,8 @@ use `electric-indent-local-mode'."
 ;;;###autoload
 (define-minor-mode electric-indent-local-mode
   "Toggle `electric-indent-mode' only in this buffer."
-  :variable (buffer-local-value 'electric-indent-mode (current-buffer))
+  :variable ( electric-indent-mode .
+              (lambda (val) (setq-local electric-indent-mode val)))
   (cond
    ((eq electric-indent-mode (default-value 'electric-indent-mode))
     (kill-local-variable 'electric-indent-mode))
@@ -484,7 +485,8 @@ The variable `electric-layout-rules' says when and how to insert newlines."
 ;;;###autoload
 (define-minor-mode electric-layout-local-mode
   "Toggle `electric-layout-mode' only in this buffer."
-  :variable (buffer-local-value 'electric-layout-mode (current-buffer))
+  :variable ( electric-layout-mode .
+              (lambda (val) (setq-local electric-layout-mode val)))
   (cond
    ((eq electric-layout-mode (default-value 'electric-layout-mode))
     (kill-local-variable 'electric-layout-mode))
@@ -661,7 +663,8 @@ use `electric-quote-local-mode'."
 ;;;###autoload
 (define-minor-mode electric-quote-local-mode
   "Toggle `electric-quote-mode' only in this buffer."
-  :variable (buffer-local-value 'electric-quote-mode (current-buffer))
+  :variable ( electric-quote-mode .
+              (lambda (val) (setq-local electric-quote-mode val)))
   (cond
    ((eq electric-quote-mode (default-value 'electric-quote-mode))
     (kill-local-variable 'electric-quote-mode))

lisp/emacs-lisp/gv.el

@@ -169,6 +169,18 @@ arguments as NAME.  DO is a function as defined in `gv-get'."
         ;; (`(expand ,expander) `(gv-define-expand ,name ,expander))
         (_ (message "Unknown %s declaration %S" symbol handler) nil))))
 
+(defun make-obsolete-generalized-variable (obsolete-name current-name when)
+  "Make byte-compiler warn that generalized variable OBSOLETE-NAME is obsolete.
+The warning will say that CURRENT-NAME should be used instead.
+
+If CURRENT-NAME is a string, that is the `use instead' message.
+
+WHEN should be a string indicating when the variable was first
+made obsolete, for example a date or a release number."
+  (put obsolete-name 'byte-obsolete-generalized-variable
+       (purecopy (list current-name when)))
+  obsolete-name)
+
 ;; Additions for `declare'.  We specify the values as named aliases so
 ;; that `describe-variable' prints something useful; cf. Bug#40491.
 
@@ -395,6 +407,7 @@ The return value is the last VAL in the list.
 (gv-define-setter buffer-local-value (val var buf)
   (macroexp-let2 nil v val
     `(with-current-buffer ,buf (set (make-local-variable ,var) ,v))))
+(make-obsolete-generalized-variable 'buffer-local-value nil "29.1")
 
 (gv-define-expander alist-get
   (lambda (do key alist &optional default remove testfn)
@@ -619,18 +632,6 @@ REF must have been previously obtained with `gv-ref'."
 
 ;;; Generalized variables.
 
-(defun make-obsolete-generalized-variable (obsolete-name current-name when)
-  "Make byte-compiler warn that generalized variable OBSOLETE-NAME is obsolete.
-The warning will say that CURRENT-NAME should be used instead.
-
-If CURRENT-NAME is a string, that is the `use instead' message.
-
-WHEN should be a string indicating when the variable was first
-made obsolete, for example a date or a release number."
-  (put obsolete-name 'byte-obsolete-generalized-variable
-       (purecopy (list current-name when)))
-  obsolete-name)
-
 ;; Some Emacs-related place types.
 (gv-define-simple-setter buffer-file-name set-visited-file-name t)
 (make-obsolete-generalized-variable

lisp/paren.el

@@ -149,7 +149,8 @@ use `show-paren-local-mode'."
 ;;;###autoload
 (define-minor-mode show-paren-local-mode
   "Toggle `show-paren-mode' only in this buffer."
-  :variable (buffer-local-value 'show-paren-mode (current-buffer))
+  :variable ( show-paren-mode .
+              (lambda (val) (setq-local show-paren-mode val)))
   (cond
    ((eq show-paren-mode (default-value 'show-paren-mode))
     (unless show-paren-mode