BUG/MINOR: threads: tid_bit must be a unsigned long

This is specific to threads, no backport is needed.
diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index 31d0f53..9782ca9 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -26,7 +26,7 @@
 
 #define MAX_THREADS_MASK ((unsigned long)-1)
 extern THREAD_LOCAL unsigned int tid;     /* The thread id */
-extern THREAD_LOCAL unsigned int tid_bit; /* The bit corresponding to the thread id */
+extern THREAD_LOCAL unsigned long tid_bit; /* The bit corresponding to the thread id */
 
 #ifndef USE_THREAD