printf_stderr now works out of the box on Windows

[Jeff Muizelaar]

15 years ago we landed a change to make printf_stderr reopen fd 2
instead of using stderr directly to work around a linking issue. This
prevented printf_stderr from showing up in the console on Windows.

I landed https://bugzilla.mozilla.org/show_bug.cgi?id=1680402 this
week to fix this.

Now you don't have to redirect fd 2 to a file to see printf_stderr.

-Jeff

[Emilio Cobos Álvarez]

First, thanks a lot for fixing this. Every single time I need to debug
something windows-specific and I had to printf something I had to
remember the right incarnation to use.

Does this work now on content processes out of the box? Or do we still
need to disable the sandbox or what not to see those?

-- Emilio