Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Correct copyright date in the BPF regression test.

Adjust BPF JIT compiler regression tests to catch up with r199603.

Merge local copy of bpf_validate() with bpf_filter.c.

Merge bpf_filter.c r182425 and add test cases for jump range checks.

While I am here, fix stupid typos in test0080.h and make it JIT compiler only.

Move comments to the right places.

Merge bpf_filter.c r182412 and remove additional local checks.

While I am here, use more realistic value for illegal code test case.

Merge bpf_filter.c r182380 and remove additional local checks
for BPF_STX and BPF_LDX|BPF_MEM instructions.

Add a test case for null filter.

Add more test cases for invalid instructions and add comments
about bpf_validate(9) issues.

Remove some hacks from regression test since bpf_filter.c builds fine now.

Add a trivial bpf filter benchmark.

Use sys/net/bpf_jitter.c instead of rolling our own version
since it is compilable on user land now.

Reflect sys/net/bpf_jitter.h changes to regression test.

Add simple bpf(9) regression tests and test cases.