Added th_self() macro

Rev: src/threads.h:1.7

src/threads.h

@@ -28,6 +28,7 @@ extern MUTEX_T interpreter_lock;
 
 #define th_create(ID,fun,arg) pthread_create(ID,&pattr,fun,arg)
 #define th_exit(foo) pthread_exit(foo)
+#define th_self() pthread_self()
 
 #define COND_T pthread_cond_t
 #define co_init(X) pthread_cond_init((X), 0)