@pinotree, are we using the system v8 in HURD?

I may put this fix in just for correctness sake (I had not noticed that patch here in the `third_party` tree before), but I tried to use as many libraries already in Debian as possible to avoid patching things that we won't be likely to use.

If not, then we will have to build with the embedded copy of v8, which is, obviously, a bummer.