Add #include <iostream> since Value.h does not include it any more.

llvm-svn: 14623
diff --git a/llvm/tools/llvm-prof/llvm-prof.cpp b/llvm/tools/llvm-prof/llvm-prof.cpp
index 5a4227e..f0e9dc7 100644
--- a/llvm/tools/llvm-prof/llvm-prof.cpp
+++ b/llvm/tools/llvm-prof/llvm-prof.cpp
@@ -21,6 +21,7 @@
 #include "Support/CommandLine.h"
 #include "llvm/System/Signals.h"
 #include <cstdio>
+#include <iostream>
 #include <map>
 #include <set>