[$] Bounded loops in BPF for the 5.3 kernel

BPF programs have gained significantly in capabilities over the last fewyears and can now perform many useful operations. That said, BPFdevelopers have had to work around an annoying limitation until recently: they could not use loops. This restriction was recently liftedby a patchset from Alexei Starovoitov that was merged for Linux 5.3. In addition toadding support for loops, it also greatly decreases the load time ofmost BPF programs.