(Background of my question is that I'm playing with clang which
doesn't support "-traditional-cpp".)
Perhaps the i386 files in question are in fact C-compatible enough to
use a standard C preprocessor, but I think it would be a bad idea to
depend on that. I'd prefer to either find/build a tradition-compatible
preprocessor for them or switch to a more generic preprocessor (eg m4).
I wrote a Reiser-compatible preprocessor ages ago, but I don't know
what's become of it; if anyone's interested I can try to scare it up.