[tex-live] adding support for MidnightBSD in tlmgr

[Nelson H. F. Beebe]

I have just successfully used my amd64-freebsd113 binaries to run a
TeX Live 2020 update on Midnight BSD 1.2, installed from the
texcol2020.iso file.  

The only glitch is that tlmgr does not recognize that system: it
reports

	tlmgr: could not guess OS from config.guess string:        \
	amd64-unknown-midnightbsd1.2 at                            \
	/usr/uumath/texlive/2020/tlpkg/TeXLive/TLUtils.pm line 325.

On that system, I find these results:

	% /usr/uumath/texlive/2020/tlpkg/installer/config.guess
	amd64-unknown-midnightbsd1.2

	% uname -s
	MidnightBSD

	% uname -r
	1.2

	% uname -m
	amd64

I have other MidnightBSD systems running versions 1.0 and 1.1.

Would some perl expert care to offer suitable patches to TLUtils.pm to
add support for MidnightBSD?  I'll be happy to test them before they
get added to the official TeX Live 2020 tree.

I have so far scrupulously avoided the perl language, and although I
did look at TLUtils.pm to see whether the changes might be trivial,
there is too much magic in perl statements for me to do that with any
confidence.

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- University of Utah                    FAX: +1 801 581 4148                  -
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