Remove residual blank line at start of Makefile

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove $FreeBSD$: one-line sh pattern

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

Provide O_SEARCH

O_SEARCH is defined by POSIX [0] to open a directory for searching, skipping
permissions checks on the directory itself after the initial open(). This is
close to the semantics we've historically applied for O_EXEC on a directory,
which is UB according to POSIX. Conveniently, O_SEARCH on a file is also
explicitly undefined behavior according to POSIX, so O_EXEC would be a fine
choice. The spec goes on to state that O_SEARCH and O_EXEC need not be
distinct values, but they're not defined to be the same value.

This was pointed out as an incompatibility with other systems that had made
its way into libarchive, which had assumed that O_EXEC was an alias for
O_SEARCH.

This defines compatibility O_SEARCH/FSEARCH (equivalent to O_EXEC and FEXEC
respectively) and expands our UB for O_EXEC on a directory. O_EXEC on a
directory is checked in vn_open_vnode already, so for completeness we add a
NOEXECCHECK when O_SEARCH has been specified on the top-level fd and do not
re-check that when descending in namei.

[0] https://pubs.opengroup.org/onlinepubs/9699919799/

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23247

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

First pass to fix the 'tests' packages.

Sponsored by: The FreeBSD Foundation

Add _test suffix to multiple tests in lib/libc to conform to the design noted
in the FreeBSD Test Suite wiki

MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division

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

Enable utimensat tests from NetBSD.

As with other tests from c063, a required #include <sys/stat.h> was missing.

Link lib/libc/c063 tests to the build.

Some files lack required #include <sys/stat.h>. The #ifdef is per ngie's
request; the includes are clearly necessary for struct stat.

The faccessat test fails because it tries to use AT_SYMLINK_NOFOLLOW with
faccessat(), which is not specified by POSIX.1-2008.

Differential Revision: https://reviews.freebsd.org/D1411
Reviewed by: ngie

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