changes to make it compatible with 64bit gcc

llvm-svn: 2790
diff --git a/llvm/lib/CWriter/Writer.cpp b/llvm/lib/CWriter/Writer.cpp
index 27db6cf..dfb8a19 100644
--- a/llvm/lib/CWriter/Writer.cpp
+++ b/llvm/lib/CWriter/Writer.cpp
@@ -26,6 +26,7 @@
 using std::string;
 using std::map;
 using std::ostream;
+using std::cerr;
 
 static std::string getConstStrValue(const Constant* CPV);