Unbreak x64 MSVC build. Patch by Nicolas Capens!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89341 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Host.cpp b/lib/System/Host.cpp
index 37591a5..e112698 100644
--- a/lib/System/Host.cpp
+++ b/lib/System/Host.cpp
@@ -22,6 +22,9 @@
 #ifdef LLVM_ON_WIN32
 #include "Win32/Host.inc"
 #endif
+#ifdef _MSC_VER
+#include <intrin.h>
+#endif
 
 //===----------------------------------------------------------------------===//
 //