[PATCH] Fix libjava breakage with glibc 2.2.2pre

[Andrew Haley]

After some offline discussion, this is what I intend to do.

1.  On the gcc 3.0 branch libgcj will use the divide subroutine.  This
    is slower than using SIGFPE but it's guaranteed to work on every
    combination of kernel and libc.

2.  On the trunk libgcj will use syscall (SYS_sigaction), which is
    faster but slightly more risky.

3.  In the somewhat longer term we can move to using SIGINFO.
    However, we need to decide whether or not we can cease to support
    older Linux kernels.

I need to do full test cycles, which means that none of this will be
checked in before tomorrow morning.

Andrew.