libpthread: Move namespacing include to top of .c files.

Stuff like libc's namespace.h, or atomic_op_namespace.h, which does
namespacing tricks like `#define atomic_cas_uint _atomic_cas_uint',
has t

libpthread: Move namespacing include to top of .c files.

Stuff like libc's namespace.h, or atomic_op_namespace.h, which does
namespacing tricks like `#define atomic_cas_uint _atomic_cas_uint',
has to go at the top of each .c file. If it goes in the middle, it
might be too late to affect the declarations, and result in compile
errors.

I tripped over this by including <sys/atomic.h> in mips
<machine/lock.h>.

(Maybe we should create a new pthread_namespace.h file for the
purpose, but this'll do for now.)

show more ...

Revert last 2 updates - these are, of course, not needed at all...

This time do _lwp_park() timeout unconsting correctly not just compilably.

Deal with more lwp_park() timestamp unconsting

remove compatibility code for handling CLOCK_MONOTONIC and handle it in the
syscall directly.

Adjust the compat stuff slightly so that the changes are mostly self
contained (Makefile, pthread_compat.c).

make PTHREAD__COMPAT=1

Builds a libpthread that can be dropped into a NetBSD 2/3/4 chroot.

This makes threading work in the chroot when using a NetBSD 5 kernel, no
other modifications required.