Added missing #includes on OpenBSD

src/common.cpp

@@ -25,6 +25,11 @@
 #include <psapi.h>
 #endif
 
+#if defined(GB_SYSTEM_OPENBSD)
+#include <sys/resource.h>
+#include <sys/wait.h>
+#endif
+
 #include <math.h>
 #include <string.h>
 #include <atomic> // Because I wanted the C++11 memory order semantics, of which gb.h does not offer (because it was a C89 library)