Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/MC/MCWinCOFFObjectWriter.h b/linux-x64/clang/include/llvm/MC/MCWinCOFFObjectWriter.h
new file mode 100644
index 0000000..3234bd9
--- /dev/null
+++ b/linux-x64/clang/include/llvm/MC/MCWinCOFFObjectWriter.h
@@ -0,0 +1,52 @@
+//===- llvm/MC/MCWinCOFFObjectWriter.h - Win COFF Object Writer -*- 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_MCWINCOFFOBJECTWRITER_H
+#define LLVM_MC_MCWINCOFFOBJECTWRITER_H
+
+#include <memory>
+
+namespace llvm {
+
+class MCAsmBackend;
+class MCContext;
+class MCFixup;
+class MCObjectWriter;
+class MCValue;
+class raw_pwrite_stream;
+
+  class MCWinCOFFObjectTargetWriter {
+    virtual void anchor();
+
+    const unsigned Machine;
+
+  protected:
+    MCWinCOFFObjectTargetWriter(unsigned Machine_);
+
+  public:
+    virtual ~MCWinCOFFObjectTargetWriter() = default;
+
+    unsigned getMachine() const { return Machine; }
+    virtual unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
+                                  const MCFixup &Fixup, bool IsCrossSection,
+                                  const MCAsmBackend &MAB) const = 0;
+    virtual bool recordRelocation(const MCFixup &) const { return true; }
+  };
+
+  /// \brief Construct a new Win COFF writer instance.
+  ///
+  /// \param MOTW - The target specific WinCOFF writer subclass.
+  /// \param OS - The stream to write to.
+  /// \returns The constructed object writer.
+  std::unique_ptr<MCObjectWriter>
+  createWinCOFFObjectWriter(std::unique_ptr<MCWinCOFFObjectTargetWriter> MOTW,
+                            raw_pwrite_stream &OS);
+} // end namespace llvm
+
+#endif // LLVM_MC_MCWINCOFFOBJECTWRITER_H