MFC note: tests/sys/kern/coredump_phnum_test.sh changes omitted

MFC r322214:

Make test scripts under tests/... non-executable

Executable bits should be set at install time instead of in the repo.
Setting executable bits on files triggers false positives with Phabricator.

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

Integrate tools/regression/acltools into the FreeBSD test suite as tests/sys/acl

- Make the requirements more complete for the testcases
- Detect prerequisites so the tests won't fail (zfs.ko is loaded, zpool(1)
is available, ACL support is enabled with UFS, etc).
- Work with temporary files/directories/mountpoints that work with atf/kyua
- Limit the testcases to work on temporary filesystems to reduce tainting the
test host

MFC after: 2 weeks
Reviewed by: trasz (earlier version)
Differential Revision: https://reviews.freebsd.org/D3810

Integrate tools/regression/acltools into tests/sys/acl

Apply patches I've been running for months on my GitHub project

Integrate tools/regression/acltools into tests/sys/acl

Apply patches I've been running for months on my GitHub project

Integrate more tests into the FreeBSD test suite from tools/regression, etc

Add ACL fuzzer. It's not used by the regression tests right now,
but I'd prefert to have it here, so it won't get lost.