cross builds and include files

[Paul Koning]

It seems I'm not the only one that keeps tripping over missing include
files in crosscompiler builds.  After running into this N times I've
developed a hack solution, but it would be nice to find documentation
for the "right" answer.

(The hack solution is: when the make cross bombs in the libgcc2 part,
copy a suitable set of h files into gcc/include.  Then reissue the
make cross.)

My guess is that the make cross process would pull the relevant h
files out of someplace on my system; but since I don't know where
from, I can't arrange for it to make them available.

By the way, libgcc2 usually compiles most of the way through but blows
up at component "bb" because that wants more h files (like stdio.h).

	oayk