Fix build on Ubuntu 10.04.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@109208 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 5b2af15..41627a5 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -34,6 +34,7 @@
 #include "llvm/System/Host.h"
 #include "llvm/System/Path.h"
 #include <cstdlib>
+#include <cstdio>
 using namespace clang;
 
 PrecompiledPreamble::~PrecompiledPreamble() {