$OpenBSD$
From upstream 64fb96e4934c7ab36acda84bdd8c36b2363e48e8.
--- Source/Core/Common/Thread.cpp.orig	Wed Jul 13 22:37:19 2016
+++ Source/Core/Common/Thread.cpp	Wed Jul 13 22:39:56 2016
@@ -12,7 +12,7 @@
 
 #ifdef __APPLE__
 #include <mach/mach.h>
-#elif defined BSD4_4 || defined __FreeBSD__
+#elif defined BSD4_4 || defined __FreeBSD__ || defined __OpenBSD__
 #include <pthread_np.h>
 #endif
 
@@ -133,7 +133,7 @@ void SetCurrentThreadName(const char* szThreadName)
 {
 #ifdef __APPLE__
 	pthread_setname_np(szThreadName);
-#elif defined __FreeBSD__
+#elif defined __FreeBSD__ || defined __OpenBSD__
 	pthread_set_name_np(pthread_self(), szThreadName);
 #else
 	// linux doesn't allow to set more than 16 bytes, including \0.