Define nonportable pthread mutex macros with the _NP suffix.

Change-Id: I1066352e5b2607f64daf6aeb0030d0bbe88ead8d
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index c32890b..334cf7a 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -56,6 +56,9 @@
 #define  PTHREAD_RECURSIVE_MUTEX_INITIALIZER   {__PTHREAD_RECURSIVE_MUTEX_INIT_VALUE __RESERVED_INITIALIZER}
 #define  PTHREAD_ERRORCHECK_MUTEX_INITIALIZER  {__PTHREAD_ERRORCHECK_MUTEX_INIT_VALUE __RESERVED_INITIALIZER}
 
+#define  PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP  PTHREAD_RECURSIVE_MUTEX_INITIALIZER
+#define  PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP PTHREAD_ERRORCHECK_MUTEX_INITIALIZER
+
 enum {
     PTHREAD_MUTEX_NORMAL = 0,
     PTHREAD_MUTEX_RECURSIVE = 1,