Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/unittests/IR/MDBuilderTest.cpp b/unittests/IR/MDBuilderTest.cpp
index 665d559..c8b5a09 100644
--- a/unittests/IR/MDBuilderTest.cpp
+++ b/unittests/IR/MDBuilderTest.cpp
@@ -9,6 +9,7 @@
 
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Metadata.h"
 #include "llvm/IR/Operator.h"
 #include "gtest/gtest.h"