You can't use config options without config.h

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22446 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/SelectionDAGPrinter.cpp

@@ -16,6 +16,7 @@
 #include "llvm/Function.h"
 #include "llvm/Support/GraphWriter.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Config/config.h"
 #include <fstream>
 using namespace llvm;