bug#6546: win32 grep/shell utf-8 encoding

[Laimonas Vėbra]

Maybe it's actually not the bug (but missing functionality), but how do 
one should/could setup ones emacs && .emacs to grep files in utf-8 
encoding?

grep 2.6.3 (cygwin) at last works correctly (coloring multibyte matches) 
from win32 console (according to LANG environment settings), but no 
matter how i've tried to push emacs (set-language-environment, 
coding-system-for-(read|write), set-env in grep-setup-hook), it just 
don't work, because somewhere inside the Emacs win32 stuff it sticks to 
windows locale codepage and tries hard to convert to this 
codepage/encoding before it passes arguments to shell. No wonder -- it 
fails when it comes to unicode.

How to reproduce:

Create utf-8 file with some unicode characters (Cyrillic, Baltic, 
whatever; not only ascii) and try to grep for some utf-8 strings from 
Emacs (M-x grep).