posix-threads.h (PTHREAD_MUTEX_IS_STRUCT): New define.
* include/posix-threads.h (PTHREAD_MUTEX_IS_STRUCT): New define.
(_Jv_PthreadGetMutex): Use it.
(_Jv_PthreadCheckMonitor): Use new M_COUNT macros.
(_Jv_MutexInit): Use PTHREAD_MUTEX_IS_STRUCT.
(_Jv_MutexLock): Likewise.
(_Jv_MutexUnlock): Likewise.
* include/config.h.in: Rebuilt.
* acconfig.h (PTHREAD_MUTEX_HAVE_M_COUNT,
PTHREAD_MUTEX_HAVE___M_COUNT): New undefs.
* configure: Rebuilt.
* libgcj.spec.in: Don't mention INTERPSPEC.
* configure.in (INTERPSPEC): Removed.
Only run pthreads-related checks when using POSIX threads. Check
for m_count and __m_count in mutex structure.