Remove $FreeBSD$: one-line sh pattern

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

Avoid using non-portable dd status=none flag

Copying the approach chosen in r309412. This fixes building the libc tests
on a macOS host since the macOS /bin/dd binary does not support status=none.

As there only seem to be two uses, this commit changes the two Makefiles.
If this becomes more common, we could also add a wrapper bootstrap script
that ignores status= and forwards the remaining args to the real dd.
Another alternative would be to remove the status flag and pipe stderr to
/dev/null, but them we lose error messages.

Reviewed By: brooks
Differential Revision: https://reviews.freebsd.org/D24785

Merge ^/user/ngie/release-pkg-fix-tests to unbreak how test files are installed
after r298107

Summary of changes:

- Replace all instances of FILES/TESTS with ${PACKAGE}FILES. This ensures that
namespacing is kept with FILES appropriately, and that this shouldn't need
to be repeated if the namespace changes -- only the definition of PACKAGE
needs to be changed
- Allow PACKAGE to be overridden by callers instead of forcing it to always be
`tests`. In the event we get to the point where things can be split up
enough in the base system, it would make more sense to group the tests
with the blocks they're a part of, e.g. byacc with byacc-tests, etc
- Remove PACKAGE definitions where possible, i.e. where FILES wasn't used
previously.
- Remove unnecessary TESTSPACKAGE definitions; this has been elided into
bsd.tests.mk
- Remove unnecessary BINDIRs used previously with ${PACKAGE}FILES;
${PACKAGE}FILESDIR is now automatically defined in bsd.test.mk.
- Fix installation of files under data/ subdirectories in lib/libc/tests/hash
and lib/libc/tests/net/getaddrinfo
- Remove unnecessary .include <bsd.own.mk>s (some opportunistic cleanup)

Document the proposed changes in share/examples/tests/tests/... via examples
so it's clear that ${PACKAGES}FILES is the suggested way forward in terms of
replacing FILES. share/mk/bsd.README didn't seem like the appropriate method
of communicating that info.

MFC after: never probably
X-MFC with: r298107
PR: 209114
Relnotes: yes
Tested with: buildworld, installworld, checkworld; buildworld, packageworld
Sponsored by: EMC / Isilon Storage Division

Remove dd xfer stats emitted during buildworld

They result in gratuitous differences when comparing build log output.

Fix another 'tests' packaging error.

Sponsored by: The FreeBSD Foundation

Refactor the test/ Makefiles after recent changes to bsd.test.mk (r289158) and
netbsd-tests.test.mk (r289151)

- Eliminate explicit OBJTOP/SRCTOP setting
- Convert all ad hoc NetBSD test integration over to netbsd-tests.test.mk
- Remove unnecessary TESTSDIR setting
- Use SRCTOP where possible for clarity

MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Divison

Add missing CLEANFILES.

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Fix t_spawnattr test for attributes handling by posix_spawn(3).
Connect it to the build.

The code assumed that SCHED_* constants form a contiguous set of
numbers, remove the assumption by using schedulers[] array in
get_different_scheduler(). This is no-op on FreeBSD, but improves
code portability.

The selection of different priority used the min/max priority range of
the current scheduler class, instead of the priority to be changed to.
The bug caused the test failure.

Remove duplication of POSIX_SPAWN_SETSIGDEF flag and now unused
duplications of MIN/MAX definitions.

Reviewed by: jilles, pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D3533

Add reachover Makefiles for contrib/netbsd-tests/lib/libc; this adds approximately
500 new testcases

Various TODOs have been sprinkled around the Makefiles for items that even need
to be ported (missing features), testcases have issues with building/linking, or
issues at runtime.

A variant of this code has been tested extensively on amd64 and i386
10-STABLE/11-CURRENT for several months without issue. It builds on other
architectures, but the code will remain off until I have prove it works on
virtual hardware or real hardware on other architectures

In collaboration with: pho, Casey Peel <casey.peel@isilon.com>
Sponsored by: EMC / Isilon Storage Division