Add a missing Makefile

Sponsored-by: EMC / Isilon Storage Division
Apply style(9)

Sponsored-by: EMC / Isilon Storage Division
Add a reminder about mqueuefs(4) on FreeBSD for t_mqueue
Integrate lib/libc/tests/tls into the build

- Reap lib/libc/tests/tls_dso
- Comment out all broken tests
- Add `#if defined(__NetBSD__)` around all #include <sys/tls.h>'s as
  it's a NetBSD-specific header.

Sponsored-by: EMC / Isilon Storage Division