Logging crashes

[Justus Winter]

Hello,

I patched my crash server to log crashes to the Mach console.  It is
nowhere near being ready for inclusion, but it might be very handy on
the build servers.

The most problematic bit of the patch is how to log the crashes.  The
patch simply includes a platform specific syscall stub.  I guess one
could just as well use the libcs generic syscall stub, but I'd love to
see the libc provide a mach_print function for everyone to use.

Cheers,
Justus