bug#26504: patch for efaq-w32.texi

[Tak Kunihiro]

>> +Emacs should be launched by @command{runemacs.exe} and referred by
>> +@command{emacsclientw.exe}.  When you choose Emacs (to be exact, a
>> +shortcut with target @command{C:\emacs-26.1\bin\runemacs.exe}) from
>> +Start menu as if a Window app, you may launch another Emacs.  To avoid
>> +having double Emacs, change target of the shortcut to
>> +@code{C:\emacs-26.1\bin\emacsclientw.exe "" --alternate-editor
>> +C:\emacs-26.1\bin\runemacs.exe}.
> 
> I'm not sure I understand what this says, but if you are saying that
> the desktop icon should invoke emacsclientw instead of runemacs, I
> think I disagree.  For starters, it's entirely possible that the user
> actually _wants_ to launch "another Emacs"; one situation where this
> happens a lot is when you work on developing Emacs and have an older
> version used for routine work (including Emacs development).  So I
> don't think we should advice users one way or another, we could at
> most describe the situation and make users aware of the subtleties, so
> that they could do what's right for their use cases.

I do not insist that the desktop icon should invoke emacsclientw
instead of runemacs.

On Windows, I suppose user launches App by choosing icon from Start
Menu.  After a while, spending minutes outside of the App, user wants
to switch back to the App.  The easiest way is choosing the same icon
from Start Menu again (without worrying if App is already running).
This works in Emacs on Mac.

Q: How do I launch and switch to Emacs by choosing the same icon in
   Start Menu?

The paragraph answers the question and shows recipe.  Since Q and A
about Windows, I thought it is good to have in FAQ.

> emacsclientw.exe "" --alternate-editor runemacs.exe

It took me a while to find out solution (that is just giving empty
argument).  If I am the one who had such a question, this is not
frequent, and I agree this should go to nowhere.