Add @kindex in manuals for existing keybindings on 'C-x x/w' (bug#13167)

* doc/emacs/buffers.texi (Misc Buffer): Add @kindex for 'C-x x r',
'C-x x u', 'C-x x i'.

* doc/emacs/display.texi (Line Truncation): Add @kindex for 'C-x x t'.

* doc/emacs/files.texi (Reverting): Add @kindex for 'C-x x g'.

* doc/emacs/windows.texi (Change Window): Use new keybinding 'C-x w 0'
instead of 'M-x delete-windows-on'.

* doc/misc/info.texi (Create Info buffer): Add @kindex for 'C-x x n'.

doc/emacs/buffers.texi

@@ -262,12 +262,14 @@ non-@code{nil}.  If you change the option @code{view-read-only} to a
 non-@code{nil} value, making the buffer read-only with @kbd{C-x C-q}
 also enables View mode in the buffer (@pxref{View Mode}).
 
+@kindex C-x x r
 @findex rename-buffer
   @kbd{C-x x r} (@code{rename-buffer} changes the name of the current
 buffer.  You specify the new name as a minibuffer argument; there is
 no default.  If you specify a name that is in use for some other
 buffer, an error happens and no renaming is done.
 
+@kindex C-x x u
 @findex rename-uniquely
   @kbd{C-x x u} (@code{rename-uniquely}) renames the current buffer to
 a similar name with a numeric suffix added to make it both different
@@ -282,6 +284,7 @@ buffers with particular names.  (With some of these features, such as
 buffer before using the command again, otherwise it will reuse the
 current buffer despite the name change.)
 
+@kindex C-x x i
   The commands @kbd{M-x append-to-buffer} and @kbd{C-x x i}
 (@code{insert-buffer}) can also be used to copy text from one buffer
 to another.  @xref{Accumulating Text}.

doc/emacs/display.texi

@@ -1986,6 +1986,7 @@ the fringe indicates truncation at either end of the line.  On text
 terminals, this is indicated with @samp{$} signs in the rightmost
 and/or leftmost columns.
 
+@kindex C-x x t
 @vindex truncate-lines
 @findex toggle-truncate-lines
   Horizontal scrolling automatically causes line truncation

doc/emacs/files.texi

@@ -1062,6 +1062,7 @@ revert it automatically if it has changed---provided the buffer itself
 is not modified.  (If you have edited the text, it would be wrong to
 discard your changes.)
 
+@kindex C-x x g
 @vindex revert-buffer-quick-short-answers
 @findex revert-buffer-quick
   The @kbd{C-x x g} keystroke is bound to the

doc/emacs/windows.texi

@@ -287,7 +287,7 @@ Delete all windows in the selected frame except the selected window
 Delete the selected window and kill the buffer that was showing in it
 (@code{kill-buffer-and-window}).  The last character in this key
 sequence is a zero.
-@item M-x delete-windows-on @key{RET} @var{buffer} @key{RET}
+@item C-x w 0 @key{RET} @var{buffer} @key{RET}
 Delete windows showing the specified @var{buffer}.
 @item C-x ^
 Make selected window taller (@code{enlarge-window}).

doc/misc/info.texi

@@ -1148,6 +1148,7 @@ move between menu items.
 @section @kbd{M-n} creates a new independent Info buffer in Emacs
 
 @kindex M-n @r{(Info mode)}
+@kindex C-x x n
 @findex clone-buffer
 @cindex multiple Info buffers
   If you are reading Info in Emacs, you can select a new independent