[tlbuild] icu-57.1 trial builds in tl

[Marc Baudoin]

Karl Berry <karl at freefriends.org> écrit :
> I just imported icu-57.1 (release) into the TL source tree, including
> the same changes that were made by peb in the last round.  (A couple of
> the patches had been applied, but most were still needed.)  I also cut
> down the huge .dat file in (I hope) the same way.
> 
> Since icu has historically been a common cause of build problems in
> multifarious unexpected ways, please give it a try.

Everything's fine on NetBSD/amd64 7.0.