[Bro] Problems compiling with --enable-int64

[Vern Paxson]

> That did not fix the problem.

Rats.  Well, this doesn't repreoduce for me (w/ g++ 4.0.1), so I'm reduced
to guessing.  The next thing I'd try is

	return new Val(abs(bro_int_t(val.int_val)), TYPE_COUNT);

but if that doesn't work, I'm not sure what next to try.

		Vern