Re: void variable

[Richard Stallman]

    + If you make a local binding for a variable defined with @code{defvar}
    + or @code{defcustom} in another non-preloaded file, and if anything in
    + the scope of the binding loads that file, for instance through
    + autoloading, then this may fail to properly initialize the variable.

This tries to describe two different problem situations which in
practice occur in different code and when doing different things.

1. Making a variable binding in certain cases.

2. Failing to add an autoload for certain variable definitions.

That they are two ways of looking at the same underlying situation is
beside the point.  Each needs to be treated in the place that relates
to the situation in which it occurs.

Case #2 belongs in the section that describes autoload cookies.  Case
#1 belongs in the section which describes `let'.  This section, about
defvar, is not the right place for either of them.  Although it has a
relation to the issue, and to both cases, this is not the best place
for either of them.

Adding a shorter note to the existing warning at the end of the node
is appropriate, but don't try to do here the jobs that should be done
in other places.

Meanwhile, let's leave this until after the new warning is
implemented.  That will change what we need to say about these cases.
There is no point writing text we will have to change very soon.