Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Rewrite pfctl_test in C to reduce testsuite run time

The new C test takes 25 seconds on QEMU-RISC-V, wheras the shell version
takes 332 seconds.

Even with the latest optimizations to atf-sh this test still takes a few
seconds to startup in QEMU. Re-writing it in C reduces the runtime for a
single test from about 2-3 seconds to less than .5 seconds. Since there
are ~80 tests, this adds up to about 3-4 minutes.
This may not seem like a big speedup, but before the recent optimizations
to avoid atf_get_srcdir, each test took almost 100 seconds on QEMU RISC-V
instead of 3. This also significantly reduces the time it takes to list
the available test cases, which speeds up running the tests via kyua:

```
root@qemu-riscv64-alex:~ # /usr/bin/time kyua test -k /usr/tests/sbin/pfctl/Kyuafile pfctl_test_old
...
158/158 passed (0 failed)
332.08 real 42.58 user 286.17 sys
root@qemu-riscv64-alex:~ # /usr/bin/time kyua test -k /usr/tests/sbin/pfctl/Kyuafile pfctl_test
158/158 passed (0 failed)
24.96 real 9.75 user 14.26 sys

root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test pf1001
pfctl_test: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Running pfctl -o none -nvf /usr/tests/sbin/pfctl/./files/pf1001.in
---
binat on em0 inet6 from fc00::/64 to any -> fc00:0:0:1::/64
binat on em0 inet6 from any to fc00:0:0:1::/64 -> fc00::/64
---
passed
0.17 real 0.06 user 0.08 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_old pf1001
pfctl_test_old: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test_old: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Id Refs Name
141 1 pf
Executing command [ pfctl -o none -nvf - ]
passed
1.73 real 0.25 user 1.41 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_old -l > /dev/null
24.36 real 2.26 user 21.86 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test -l > /dev/null
0.04 real 0.02 user 0.01 sys
```

The speedups are even more noticeable on CHERI-RISC-V (since QEMU runs
slower when emulating CHERI instructions):
```
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_new -l > /dev/null
0.51 real 0.49 user 0.00 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test -l > /dev/null
34.20 real 32.69 user 0.16 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test pf1001
pfctl_test: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Id Refs Name
147 1 pf
Executing command [ pfctl -o none -nvf - ]
passed
5.74 real 5.41 user 0.03 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_new pf1001
pfctl_test_new: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test_new: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Running pfctl -o none -nvf /usr/tests/sbin/pfctl/./files/pf1001.in
---
binat on em0 inet6 from fc00::/64 to any -> fc00:0:0:1::/64
binat on em0 inet6 from any to fc00:0:0:1::/64 -> fc00::/64
---
passed
0.68 real 0.66 user 0.00 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl #
```

Reviewed By: kp
Differential Revision: https://reviews.freebsd.org/D26779

pkgbase: pfctl: tests: Put tests files in the FreeBSD-tests package

Reviewed by: kp, gjb
Differential Revision: https://reviews.freebsd.org/D21521

pfctl test: Add a test for macro names with a space in it

pfctl parser tests

Copy the most important test cases from OpenBSD's corresponding
src/regress/sbin/pfctl, those that run pfctl on a test input file and check
correctness of its output. We have also added some new tests using the same
format.

The tests consist of a collection of input files (pf*.in) and
corresponding output files (pf*.ok). We run pfctl -nv on the input
files and check that the output matches the output files. If any
discrepancy is discovered during future development in the source
tree, we know that a regression bug has been introduced into the tree.

Submitted by: paggas
Sponsored by: Google, Inc (GSoC 2017)
Differential Revision: https://reviews.freebsd.org/D11322