net/tap: add eBPF bytes code

net/tap: add eBPF bytes code

File tap_bpf_insns.h was added. It includes  eBPF bytes code
which corresponds to source file tap_bpf_program.c
(see "net/tap: add eBPF program file").
The bytes code is in the format of C arrays of struct bpf_insn and
was generated from the C file tap_bpf_program.c
1. The C file was compiled via LLVM into an object file in ELF
format as:
   clang -O2 -emit-llvm -c tap_bpf_program.c -o - | llc -march=bpf \
   -filetype=obj -o <tap_bpf_program.o>

clang version must be 3.7 and above
The C functions are under different ELF sections and are considered
different BPF programs to be downloaded to the kernel

2. Using an external tool the ELF sections are parsed and the C arrays
of struct bpf_insn are generated. Each C array (corresponding to a
different function under an ELF section) is downloaded to the kernel
using an BPF systm call. The external tool that generates the C arrays
will be added in separate commits.

Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
Acked-by: Pascal Mazon <pascal.mazon@6wind.com>