correctly detect adaptive mutexes in pthreads

PTHREAD_MUTEX_ADAPTIVE_NP is an enum on glibc and not a macro,
we must test for their existence by attempting compilation.

include/jemalloc/internal/mutex.h

@@ -10,7 +10,7 @@ typedef struct malloc_mutex_s malloc_mutex_t;
 #elif (defined(JEMALLOC_MUTEX_INIT_CB))
 #  define MALLOC_MUTEX_INITIALIZER {PTHREAD_MUTEX_INITIALIZER, NULL}
 #else
-#  if (defined(PTHREAD_MUTEX_ADAPTIVE_NP) &&				\
+#  if (defined(JEMALLOC_HAVE_PTHREAD_MUTEX_ADAPTIVE_NP) &&		\
        defined(PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP))
 #    define MALLOC_MUTEX_TYPE PTHREAD_MUTEX_ADAPTIVE_NP
 #    define MALLOC_MUTEX_INITIALIZER {PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP}