Removed obsolete intermediate threading layer.
* thr.c: Use __gthread_objc_xxx functions directly instead of
__objc_thread_xxx ones.
* objc/thr.h: Removed prototypes of no longer existing
__objc_thread_xxx functions.
* Makefile.in: Removed thr-objc.lo.
* thr-dce.c: File removed.
* thr-decosf1.c: File removed.
* thr-irix.c: File removed.
* thr-mach.c: File removed.
* thr-objc.c: File removed.
* thr-os2.c: File removed.
* thr-posix.c: File removed.
* thr-pthreads.c: File removed.
* thr-rtems.c: File removed.
* thr-single.c: File removed.
* thr-solaris.c: File removed.
* thr-vxworks.c: File removed.
* thr-win32.c: File removed.
* README.threads: File removed.
* THREADS.MACH: File removed.
* THREADS: Updated.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@163996
138bc75d-0d04-0410-961f-
82ee72b054a4