Include <tuple> to make buildbots happy

llvm-svn: 211949
diff --git a/llvm/lib/Linker/LinkModules.cpp b/llvm/lib/Linker/LinkModules.cpp
index eb73a49..5bb2862 100644
--- a/llvm/lib/Linker/LinkModules.cpp
+++ b/llvm/lib/Linker/LinkModules.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 #include <cctype>
+#include <tuple>
 using namespace llvm;