Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/MC/MCSymbolELF.h b/linux-x64/clang/include/llvm/MC/MCSymbolELF.h
new file mode 100644
index 0000000..bbcd22e
--- /dev/null
+++ b/linux-x64/clang/include/llvm/MC/MCSymbolELF.h
@@ -0,0 +1,54 @@
+//===- MCSymbolELF.h -  -----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_MC_MCSYMBOLELF_H
+#define LLVM_MC_MCSYMBOLELF_H
+
+#include "llvm/MC/MCSymbol.h"
+
+namespace llvm {
+class MCSymbolELF : public MCSymbol {
+  /// An expression describing how to calculate the size of a symbol. If a
+  /// symbol has no size this field will be NULL.
+  const MCExpr *SymbolSize = nullptr;
+
+public:
+  MCSymbolELF(const StringMapEntry<bool> *Name, bool isTemporary)
+      : MCSymbol(SymbolKindELF, Name, isTemporary) {}
+  void setSize(const MCExpr *SS) { SymbolSize = SS; }
+
+  const MCExpr *getSize() const { return SymbolSize; }
+
+  void setVisibility(unsigned Visibility);
+  unsigned getVisibility() const;
+
+  void setOther(unsigned Other);
+  unsigned getOther() const;
+
+  void setType(unsigned Type) const;
+  unsigned getType() const;
+
+  void setBinding(unsigned Binding) const;
+  unsigned getBinding() const;
+
+  bool isBindingSet() const;
+
+  void setIsWeakrefUsedInReloc() const;
+  bool isWeakrefUsedInReloc() const;
+
+  void setIsSignature() const;
+  bool isSignature() const;
+
+  static bool classof(const MCSymbol *S) { return S->isELF(); }
+
+private:
+  void setIsBindingSet() const;
+};
+}
+
+#endif