* src/editfns.c: (Finternal__labeled_widen): Add a call to
'Fwiden', and rename from 'internal--unlabel-restriction'.
(unwind_labeled_narrow_to_region): Use the renamed function, and
remove the call to 'Fwiden'.
(syms_of_editfns): Rename the symbol.

* lisp/subr.el (internal--without-restriction): Use the renamed
function.

* src/editfns.c: (Finternal__labeled_narrow_to_region): Merge the
code of Finternal__label_restriction into this function.
(Finternal__label_restriction): Remove this function.
(syms_of_editfns): Remove the 'outermost-restriction' buffer local
variable, which is not used anymore, and the symbol of
'internal--label-restriction'.
(Fwiden): Remove the call to reset the 'outermost-restriction'
buffer local variable.

* src/editfns.c (Finternal__labeled_narrow_to_region): New
function.  A specific function is necessary to avoid unnecessary
slowdowns when 'narrow-to-region'/'widen' are called in a loop.
(Fnarrow_to_region): Remove the call to Fset, which has been moved
into Finternal__labeled_narrow_to_region.
(labeled_narrow_to_region): Use the new function.
(syms_of_editfns): Add the symbol of the new function.

* lisp/subr.el (internal--with-restriction): Use the new function.

* doc/lispref/keymaps.texi (Key Binding Commands): Improve the
documentation of arguments expected by key binding commands.

* lisp/keymap.el (keymap-set, keymap-global-set)
(keymap-local-set, keymap-global-unset, keymap-local-unset)
(keymap-unset, key-parse): Doc fixes.

* lisp/emacs-lisp/shortdoc.el (number): Make it clear that zero
satisfies 'natnump'.  Move 'natnump' next to 'cl-plusp' to highlight
the difference between them.

* doc/lispref/debugging.texi (Profiling): 'benchmark-call' is a defun,
not a macro.

Instead of the incorrect key `M-c' produce the right key
with \\<read-regexp-map>\\[read-regexp-toggle-case-fold].

* doc/emacs/mini.texi (Completion Commands): Index more keys and
commands.  (Bug#64425)

* doc/lispref/keymaps.texi (Functions for Key Lookup): Fix typos
in function names.  (Bug#64434)