bug#36887: coreutils-8.31: printf chokes on \u0041

[Paul Eggert]

Ulrich Mueller wrote:
> Except for the surrogates
> U+D800...U+DFFF, it looks like an arbitrary restriction

It's not entirely arbitrary. Because of the restriction, coreutils printf 
doesn't have to worry about what this command should do:

  printf '\u0025d\n' 1 2

Does this print a single line "%d", or two lines "1" and "2"? There are good 
arguments either way, and one can easily construct even-stranger examples.