Fix header file include order in NVPTX backend   NV_CONTRIB

llvm-svn: 158013
diff --git a/llvm/lib/Target/NVPTX/NVPTX.h b/llvm/lib/Target/NVPTX/NVPTX.h
index 8ec8eb3..a8d082a 100644
--- a/llvm/lib/Target/NVPTX/NVPTX.h
+++ b/llvm/lib/Target/NVPTX/NVPTX.h
@@ -15,13 +15,13 @@
 #ifndef LLVM_TARGET_NVPTX_H
 #define LLVM_TARGET_NVPTX_H
 
-#include <cassert>
-#include <iosfwd>
 #include "llvm/Value.h"
 #include "llvm/Module.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Target/TargetMachine.h"
 #include "MCTargetDesc/NVPTXBaseInfo.h"
+#include <cassert>
+#include <iosfwd>
 
 namespace llvm {
 class NVPTXTargetMachine;