Gabriele Greco wrote:
Try with a prebuilt SDL version
I fixed it! Thanks Gabriele, your suggestion led me onto the right track.
It didn’t occur to me that I could use a precompiled version because I
didn’t realize that it needn’t be precompiled specifically for Mac OS X/
PPC since it only contains Windows/x86 code. Anyway, the precompiled
version from libsdl.org worked, so I went back to my own compile to figure
out what’s wrong, and eventually found it.
The problem is the following: When run through cross-configure.sh,
configure (for some reason I don’t even want to know) fails to figure out
in what shell it is running, leaving CONFIG_SHELL empty. This propagates
through various errors into a broken libtool, which in turn builds a
broken library. (Apparently the method with nm is not suitable for
detecting a broken library.)
My (preliminary) fix is to add "CONFIG_SHELL=/bin/sh; export CONFIG_SHELL"
to cross-configure.sh.
So my cross-compiler works now, and the test programs do run on a Windows
machine. 
-Christian