Push to XDP2

HI,

I pushed a new set of patches to XDP2. There is an API change. We
reduced the number of arguments for the extract metadata and handler
op function from six to five. This is needed to appease the eBPF
verifier.

Other changes include:
  - Utility defs for page size, in range macro, simple rotate word
left or right, round up, and log2 macros, XDP2_MIN, XDP2_MAX
  - Address translation functions
  - FIFOs
  - static_assert macro
  - Other fixes

Also, the XDP samples are failing to load the xdp.o files due to
incompatibility with the new eBPF style. Working on it.

Tom