Merge branch 'km/bsd-sysctl'

We now detect number of CPUs on older BSD-derived systems.

* km/bsd-sysctl:
  thread-utils.c: detect CPU count on older BSD-like systems
  configure: support HAVE_BSD_SYSCTL option

git-compat-util.h

@@ -127,6 +127,9 @@
 #else
 #include <poll.h>
 #endif
+#ifdef HAVE_BSD_SYSCTL
+#include <sys/sysctl.h>
+#endif
 
 #if defined(__MINGW32__)
 /* pull in Windows compatibility stuff */