bug#35766: emacs saves utf-16 le xml files as utf-16 be

[Eli Zaretskii]

> From: J S <jszabo_98@hotmail.com>
> CC: "npostavs@gmail.com" <npostavs@gmail.com>, "35766@debbugs.gnu.org"
>       <35766@debbugs.gnu.org>
> Date: Fri, 17 May 2019 20:16:41 +0000
> 
> For example, if I save this xml file in emacs, it saves it as utf-16 big 
> endian:
> 
> <?xml version="1.0" encoding="UTF-16"?>

This is the Emacs default, which is well documented, and is also
according to what the UTF-16 spec (RFC 2781) says.

> If I do this in powershell (really a .net method), it saves it as utf-16 
> little endian (osx or windows):

Then PowerShell behaves in violation of RFC 2781.