[tlbuild] dvisvgm-3.0.1

[Karl Berry]

Hi Dick,

    filter-neon-intrinsics.c
    ...
    The Ghostscript version reads (only 4 or 5 lines from the top)
    #if defined(_MSC_VER) && defined(_M_ARM64)

    The corresponding TL code at the same spot reads
    #if defined(_MSC_VER) && !defined(__clang__) && defined(_M_ARM64)

    [...] Do you know why these are different?

Looking at the original source tree:
https://sourceforge.net/p/libpng/code/ci/master/tree/arm/filter_neon_intrinsics.c

evidently gs has patched the file. I am doubtful of copying in their
change, since, as you've noted, this whole area is a big mishmash.

    This isn't a big deal, of course, but it would be nice to chase it down.

If a report can be put together to send upstream
(https://sourceforge.net/p/libpng/bugs/), maybe something will
happen. Otherwise, probably not.

If you want to pursue it, I suggest downloading the original libpng source:
  https://sourceforge.net/projects/libpng/files/libpng16/1.6.39/libpng-1.6.39.tar.gz/download
and seeing if it compiles on your arm machine.
If yes -> TL problem.
If no -> libpng problem.

Or so it seems to me, anyway. --thanks, karl.