Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/LTO/legacy/UpdateCompilerUsed.h b/linux-x64/clang/include/llvm/LTO/legacy/UpdateCompilerUsed.h
new file mode 100644
index 0000000..4be0027
--- /dev/null
+++ b/linux-x64/clang/include/llvm/LTO/legacy/UpdateCompilerUsed.h
@@ -0,0 +1,32 @@
+//==------ UpdateCompilerUsed.h - LLVM Link Time Optimizer Utility --------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares a helper class to update llvm.compiler_used metadata.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LTO_UPDATE_COMPILER_USED_H
+#define LLVM_LTO_UPDATE_COMPILER_USED_H
+
+#include "llvm/ADT/StringSet.h"
+#include "llvm/IR/GlobalValue.h"
+
+namespace llvm {
+class Module;
+class TargetMachine;
+
+/// Find all globals in \p TheModule that are referenced in
+/// \p AsmUndefinedRefs, as well as the user-supplied functions definitions that
+/// are also libcalls, and create or update the magic "llvm.compiler_used"
+/// global in \p TheModule.
+void updateCompilerUsed(Module &TheModule, const TargetMachine &TM,
+ const StringSet<> &AsmUndefinedRefs);
+}
+
+#endif // LLVM_LTO_UPDATE_COMPILER_USED_H