target/10338: [3.3 regression?] [Cygwin -> tic4x | avr] cross target compilation error

[Garen]

I ran into the same problem here (PR10198):
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10198

So I don't think it's a regression.  It seems to be present on all of the 
3.2.x branches, so I'm guessing it's a Cygwin problem.  I worked around it 
similarly by just not using __memcpy(), and instead memcpy() in the #else 
branch.