Work on Windows port by Ruben Van Boxem

llvm-svn: 140384
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: dbe8111948d372a6f7445e86a0ac985717fbe1bc
diff --git a/src/thread.cpp b/src/thread.cpp
index 4ccff32..b07f8f8 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -12,7 +12,9 @@
 #include "vector"
 #include "future"
 #include <sys/types.h>
+#if !_WIN32
 #include <sys/sysctl.h>
+#endif // _WIN32
 
 _LIBCPP_BEGIN_NAMESPACE_STD