Add a comment about the requirement that the Windows.h header be last.
This comment has the dual effect of blocking reorderings with the
sort_include script.

llvm-svn: 169221
diff --git a/llvm/lib/Support/Windows/Memory.inc b/llvm/lib/Support/Windows/Memory.inc
index cb80f28..4c5aebd 100644
--- a/llvm/lib/Support/Windows/Memory.inc
+++ b/llvm/lib/Support/Windows/Memory.inc
@@ -15,6 +15,8 @@
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Process.h"
+
+// The Windows.h header must be the last one included.
 #include "Windows.h"
 
 namespace {