pthread: Make pthread_np.h self-contained

[markj]

Summary

Including param.h from a standard header is inappropriate. param.h
defines all sorts of crap which collides with commonly used identifiers.
I discovered this while trying to build an old version of QEMU which
polluted its namespace by including pthread_np.h->sys/param.h, which
defines FSCALE, which breaks QEMU code.

[kib]

include/pthread_np.h

37

I think this must be sys/types.h.

In the man pages, pthread_attr_getaffinity_np() is documented to take size_t. It is natural for consumer to conclude that including pthread_np.h implies availability of size_t.

Then the change of size_t to __size_t in prototypes can be reverted.

[markj]

Include sys/types.h instead of sys/_types.h