Merge from origin/emacs-28

067361f3a2 ; Improve documentation of 'C-M-i'
fdb6f7cf26 ; Fix documentation of 'comp-enable-subr-trampolines'
be30369e01 ; Avoid incorrect indentation in an @example.
4bd3dd505e Document how to control where the *.eln files are written
b7d7c2d9e9 Add cross-reference to alternative syntaxes for Unicode

# Conflicts:
#	doc/emacs/custom.texi

diff --cc doc/emacs/custom.texi
Simple merge

diff --cc doc/emacs/programs.texi
index 30c7f106e5066122df333cd9c4c3c6045c09b9cf,a0c044b920f6ec5e9b6dbe4b09c2a0fc4c6606c8..818deb3941520039ae04ed488e4c800ae75c6b67
--- 1/doc/emacs/programs.texi
--- 2/doc/emacs/programs.texi
+++ b/doc/emacs/programs.texi
@@@ -1434,23 -1413,36 +1428,40 @@@ but you can also complete symbol names 
  @cindex Lisp symbol completion
  @cindex completion (Lisp symbols)
    In most programming language modes, @kbd{C-M-i} (or
- @kbd{M-@key{TAB}}) invokes the command @code{completion-at-point},
- which generates its completion list in a flexible way.  If Semantic
- mode is enabled, it tries to use the Semantic parser data for
- completion (@pxref{Semantic}).  If Semantic mode is not enabled or
- fails at performing completion, it tries to complete using the
- selected tags table (@pxref{Tags Tables}).  If in Emacs Lisp mode, it
- performs completion using the function, variable, or property names
- defined in the current Emacs session.
+ @kbd{M-@key{TAB}}@footnote{
+ On graphical displays, the @kbd{M-@key{TAB}} key is usually reserved
+ by the window manager for switching graphical windows, so you should
+ type @kbd{C-M-i} or @kbd{@key{ESC} @key{TAB}} instead.
+ }) invokes the command @code{completion-at-point}, which generates the
+ list of possible completions for the symbol at point.  This command
+ uses the available support facilities to come up with the completion
+ candidates:
+ 
+ @itemize @bullet
+ @item
+ If Semantic mode is enabled (@pxref{Semantic}), the command tries to
+ use the Semantic parser data for completion.
+ 
+ @item
+ If Semantic mode is not enabled or fails at performing completion, the
+ command tries to complete using the selected tags table (@pxref{Tags
+ Tables}); you need to visit the tags table with @w{@kbd{M-x
+ visit-tags-table}} for that to work.
+ 
+ @item
+ In Emacs Lisp mode, the command performs completion using the
+ function, variable, or property names defined in the current Emacs
+ session.
+ @end itemize
  
    In all other respects, in-buffer symbol completion behaves like
 -minibuffer completion.  For instance, if Emacs cannot complete to a
 -unique symbol, it displays a list of completion alternatives in
 -another window.  @xref{Completion}.
 +minibuffer completion.  For instance, if Emacs cannot complete to
 +a unique symbol, it displays a list of completion alternatives in
 +another window.  Then you can use the keys @kbd{M-@key{DOWN}} and
 +@kbd{M-@key{UP}} to navigate through the completions displayed
 +in the completions buffer without leaving the original buffer,
 +and the key @kbd{M-@key{RET}} to insert the currently highlighted
 +completion to the buffer.  @xref{Completion}.
  
    In Text mode and related modes, @kbd{M-@key{TAB}} completes words
  based on the spell-checker's dictionary.  @xref{Spelling}.

diff --cc doc/lispref/compile.texi
Simple merge

diff --cc doc/lispref/modes.texi
Simple merge

diff --cc src/comp.c
Simple merge