<pthread.h> fixes and pthread cleanup.

<pthread.h> was missing nonnull attributes, noreturn on pthread_exit,
and had incorrect cv qualifiers for several standard functions.

I've also marked the non-standard stuff (where I count glibc rather
than POSIX as "standard") so we can revisit this cruft for LP64 and
try to ensure we're compatible with glibc.

I've also broken out the pthread_cond* functions into a new file.

I've made the remaining pthread files (plus ptrace) part of the bionic code
and fixed all the warnings.

I've added a few more smoke tests for chunks of untested pthread functionality.

We no longer need the libc_static_common_src_files hack for any of the
pthread implementation because we long since stripped out the rest of
the armv5 support, and this hack was just to ensure that __get_tls in libc.a
went via the kernel if necessary.

This patch also finishes the job of breaking up the pthread.c monolith, and
adds a handful of new tests.

Change-Id: Idc0ae7f5d8aa65989598acd4c01a874fe21582c7

libc/private/bionic_pthread.h

@@ -35,7 +35,6 @@ __BEGIN_DECLS
 
 /* Internal, not an NDK API */
 extern pid_t __pthread_gettid(pthread_t thid);
-extern int __pthread_settid(pthread_t thid, pid_t tid);
 
 __END_DECLS