Patch/Ada: Implement __gnat_set_filetime_name for w32 targets

[Jerry van Dijk]

> Tested on gcc version 3.3 20021219 (prerelease)  with mingw32.	 

hmmm, today:

C:\home\src\gcc\gcc\ada>patch -p0 < ..\..\..\diffs\adapatch-20021220.diff
patching file adaint.c
Hunk #1 FAILED at 766.
1 out of 3 hunks FAILED -- saving rejects to file adaint.c.rej

--  Jerry van Dijk   | email: jdijk@acm.org
--  Leiden, Holland  | web:   users.ncrvnet.nl/gmvdijk