Spam more macros from NetBSD here and there for ATF tests

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Integrate in the librt testcases from NetBSD

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Merge branch 'atf-tools-regression-convert' of github.com:/yaneurabeya/freebsd into atf-tools-regression-convert
Shuffle around NetBSD compat macros and add __UNCONST

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Move the libc testcases from NetBSD to lib/libc/tests

Also, remove netbsd_compat.h

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>