bug#12908: 24.3.50; file `emacs_backtrace.txt'?

[Paul Eggert <eggert@cs.ucla.edu>]

There seems to be some misunderstanding here.  The Unix code does
not write into $HOME/backtrace.txt, or into $HOME, or into anywhere
like that.  It writes to stderr.  The programs that invoke Emacs
(normally window managers) arrange for the standard error stream
to be sent to a suitable place.

The Microsoft Windows code does something different: it writes the
backtrace both to stderr and to a file emacs_backtrace.txt.

If the goal is to mimic the Unix behavior as closely as possible, then
the fix should be simple: output the backtrace just to stderr, as
the Unix code does.  Perhaps there are reasons not to do that
on Microsoft Windows, but as these reasons are specific to that
platform it would seem that any fix would be platform-specific
as well.