stub thread affinity stuff

Index: rts/System/Platform/ThreadAffinityGuard.cpp
--- rts/System/Platform/ThreadAffinityGuard.cpp.orig
+++ rts/System/Platform/ThreadAffinityGuard.cpp
@@ -6,12 +6,15 @@
 #else
 #include <sched.h>
 #include <unistd.h>
+#ifndef __OpenBSD__
 #include <syscall.h>
 #endif
+#endif
 
 // Constructor: Saves the current thread's affinity
 ThreadAffinityGuard::ThreadAffinityGuard() : affinitySaved(false) {
-#ifdef _WIN32
+#ifdef __OpenBSD__
+#elif defined(_WIN32)
 	threadHandle = GetCurrentThread();  // Get the current thread handle
 	savedAffinity = SetThreadAffinityMask(threadHandle, ~0);
 	affinitySaved = ( savedAffinity != 0 );
@@ -32,7 +35,8 @@ ThreadAffinityGuard::ThreadAffinityGuard() : affinityS
 // Destructor: Restores the saved affinity if it was successfully stored
 ThreadAffinityGuard::~ThreadAffinityGuard() {
 	if (affinitySaved) {
-#ifdef _WIN32
+#ifdef __OpenBSD__
+#elif defined(_WIN32)
 		if (!SetThreadAffinityMask(threadHandle, savedAffinity)) {
 			LOG_L(L_WARNING, "SetThreadAffinityMask failed with error code: %lu", GetLastError());
 		}
