Disabling libjava on platforms in which it won't build

[Tom Tromey]

>>>>> "Alexandre" == Alexandre Oliva <aoliva@redhat.com> writes:

Alexandre> Mark, may I go ahead and enable the Java front-end by
Alexandre> default now?  It seems that the only ports that still have
Alexandre> libgcj enabled are:

Alexandre> GNU/Linux (all architectures), ia64-elf, Mingw32, Cygwin,
Alexandre> Solaris/x86 (all versions), Solaris/sparc (all versions
Alexandre> except Solaris 8), beos/x86, sparc-elf and sparc64-elf

Cygwin doesn't build right now.  There are some patches pending that
should make it work, but I haven't looked at them yet.  I'm not even
certain they should go on the 3.0 branch (opinions?  I still don't
have a very clear idea of what we want to classify as important enough
for the branch).

I have never tried a beos build of libgcj.  I doubt it would work.  I
think disabling it would be appropriate.

Tom