This makes it possible provide operating system specific types for
<pthread.h>. It is in line with the FreeBSD header file structure and
allows a future cleanup of <pthread.h> to not expose unrelated things
via <sys/types.h> and <unistd.h>. Glibc uses the similar
<bits/pthreadtypes.h> for this purpose.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
e655d3d34b