Edebug: Overload `edebug-form-spec` even less

The `edebug-form-spec` symbol property was used both to map forms's
head symbol to the corresponding spec, and to map spec element names
to their expansion.

This lead to name conflicts which break instrumentation of examples such as

    (cl-flet ((gate (x) x)) (gate 4))

because of the Edebug spec element `gate`.
So introduce a new symbol property `edebug-elem-spec`.

* lisp/subr.el (def-edebug-elem-spec): New function.

* lisp/emacs-lisp/edebug.el (edebug--get-elem-spec): New function.
(edebug-match-symbol): Use it.
(Core Edebug elems): Put them on `edebug-elem-spec` instead of
`edebug-form-spec`.
(ELisp special forms): Set their `edebug-form-spec` via dolist.
(Other non-core Edebug elems): Use `def-edebug-elem-spec`.
(edebug-\`): Use `declare`.

* lisp/emacs-lisp/pcase.el (pcase-PAT, pcase-FUN, pcase-QPAT):
* lisp/skeleton.el (skeleton-edebug-spec):
* lisp/emacs-lisp/cl-macs.el: Use `def-edebug-elem-spec`.

* test/lisp/emacs-lisp/edebug-tests.el
(edebug-tests--conflicting-internal-names): New test.
* test/lisp/emacs-lisp/edebug-resources/edebug-test-code.el
(edebug-test-code-cl-flet1): New test case.

* doc/lispref/edebug.texi (Specification List): Add `def-edebug-elem-spec`.
(Specification Examples): Use it.

* doc/lispref/loading.texi (Hooks for Loading): Avoid the use of
`def-edebug-spec` in example (better use `debug` declaration).

1 files changed, 13 insertions, 14 deletions

diff --git a/lisp/emacs-lisp/pcase.el b/lisp/emacs-lisp/pcase.el
index d6c96c1ec82..5d428ac846a 100644
--- a/lisp/emacs-lisp/pcase.el
+++ b/lisp/emacs-lisp/pcase.el
@@ -62,15 +62,14 @@
 
 (defvar pcase--dontwarn-upats '(pcase--dontcare))
 
-(def-edebug-spec pcase-PAT
-  (&or (&lookup symbolp pcase--get-edebug-spec)
-       sexp))
+(def-edebug-elem-spec 'pcase-PAT
+  '(&or (&lookup symbolp pcase--get-edebug-spec) sexp))
 
-(def-edebug-spec pcase-FUN
-  (&or lambda-expr
-       ;; Punt on macros/special forms.
-       (functionp &rest form)
-       sexp))
+(def-edebug-elem-spec 'pcase-FUN
+  '(&or lambda-expr
+        ;; Punt on macros/special forms.
+        (functionp &rest form)
+        sexp))
 
 ;; Only called from edebug.
 (declare-function edebug-get-spec "edebug" (symbol))
@@ -925,13 +924,13 @@ Otherwise, it defers to REST which is a list of branches of the form
        (t (error "Unknown pattern `%S'" upat)))))
    (t (error "Incorrect MATCH %S" (car matches)))))
 
-(def-edebug-spec pcase-QPAT
+(def-edebug-elem-spec 'pcase-QPAT
   ;; Cf. edebug spec for `backquote-form' in edebug.el.
-  (&or ("," pcase-PAT)
-       (pcase-QPAT [&rest [&not ","] pcase-QPAT]
-		   . [&or nil pcase-QPAT])
-       (vector &rest pcase-QPAT)
-       sexp))
+  '(&or ("," pcase-PAT)
+        (pcase-QPAT [&rest [&not ","] pcase-QPAT]
+		    . [&or nil pcase-QPAT])
+	(vector &rest pcase-QPAT)
+	sexp))
 
 (pcase-defmacro \` (qpat)
   "Backquote-style pcase patterns: \\=`QPAT