[kaffe] nb1.6 build fail

[Kiyo Inaba]

Latest snap failed to be compiled on NetBSD 1.6 (ia32).

Error log said,
In file included from ../../config/md.h:1,
                 from ../../../kaffe-snap-050707/kaffe/kaffeh/../kaffevm/classMethod.h:18,
                 from ../../../kaffe-snap-050707/kaffe/kaffeh/support.c:26:
../../config/../../kaffe-snap-050707/config/i386/netbsd1/md.h:35: sys/ucontext.h: No such file or directory
gmake[1]: *** [kaffeh-support.o] Error 1

Kiyo