Stop keeping multiple doc copies for items defined multiple times

It was always a nuisance to keep all the copies in sync.
* src/doc.c (Fsnarf_documentation): Don't skip entire files.
Instead, skip individual doc strings starting with "SKIP".
* doc/lispref/internals.texi (Writing Emacs Primitives):
Mention this skipping.
* lisp/term/ns-win.el, lisp/term/pc-win.el, src/dosfns.c:
* src/frame.c, src/nsfns.m, src/nsmenu.m, src/nsterm.m:
* src/w16select.c, src/w32fns.c, src/w32menu.c, src/w32select.c:
* src/w32term.c, src/xmenu.c: Remove duplicated doc strings.
* src/xfns.c: Merge in information from doc string duplicates.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nsmenu.m b/src/nsmenu.m
index 58b45fb38e5..29b0f99e642 100644
--- a/src/nsmenu.m
+++ b/src/nsmenu.m
@@ -1874,7 +1874,7 @@ DEFUN ("ns-reset-menu", Fns_reset_menu, Sns_reset_menu, 0, 0, 0,
 
 
 DEFUN ("menu-or-popup-active-p", Fmenu_or_popup_active_p, Smenu_or_popup_active_p, 0, 0, 0,
-       doc: /* Return t if a menu or popup dialog is active.  */)
+       doc: /* SKIP: real doc in xmenu.c. */)
      (void)
 {
   return popup_activated () ? Qt : Qnil;