Make iostream #inclusion explicit

llvm-svn: 25514
diff --git a/llvm/lib/Transforms/LevelRaise.cpp b/llvm/lib/Transforms/LevelRaise.cpp
index d360468..943000c 100644
--- a/llvm/lib/Transforms/LevelRaise.cpp
+++ b/llvm/lib/Transforms/LevelRaise.cpp
@@ -24,6 +24,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 #include <algorithm>
+#include <iostream>
 using namespace llvm;
 
 // StartInst - This enables the -raise-start-inst=foo option to cause the level