Fix another function val reference counting bug.

Now that functions get unref'd in the val dtor in order to free mem of
unserialized functions, it's important to ref a function when creating a
val from a pre-existing function so it's not prematurely free'd.

src/Val.cc

@@ -30,6 +30,7 @@
 Val::Val(Func* f)
 	{
 	val.func_val = f;
+	::Ref(val.func_val);
 	type = f->FType()->Ref();
 	attribs = 0;
 #ifdef DEBUG