Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/MC/MCWasmObjectWriter.h b/linux-x64/clang/include/llvm/MC/MCWasmObjectWriter.h
new file mode 100644
index 0000000..a4d5eb8
--- /dev/null
+++ b/linux-x64/clang/include/llvm/MC/MCWasmObjectWriter.h
@@ -0,0 +1,53 @@
+//===-- llvm/MC/MCWasmObjectWriter.h - Wasm 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_MCWASMOBJECTWRITER_H
+#define LLVM_MC_MCWASMOBJECTWRITER_H
+
+#include "llvm/ADT/Triple.h"
+#include "llvm/BinaryFormat/Wasm.h"
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+class MCFixup;
+class MCObjectWriter;
+class MCValue;
+class raw_pwrite_stream;
+
+class MCWasmObjectTargetWriter {
+  const unsigned Is64Bit : 1;
+
+protected:
+  explicit MCWasmObjectTargetWriter(bool Is64Bit_);
+
+public:
+  virtual ~MCWasmObjectTargetWriter();
+
+  virtual unsigned getRelocType(const MCValue &Target,
+                                const MCFixup &Fixup) const = 0;
+
+  /// \name Accessors
+  /// @{
+  bool is64Bit() const { return Is64Bit; }
+  /// @}
+};
+
+/// \brief Construct a new Wasm writer instance.
+///
+/// \param MOTW - The target specific Wasm writer subclass.
+/// \param OS - The stream to write to.
+/// \returns The constructed object writer.
+std::unique_ptr<MCObjectWriter>
+createWasmObjectWriter(std::unique_ptr<MCWasmObjectTargetWriter> MOTW,
+                       raw_pwrite_stream &OS);
+
+} // End llvm namespace
+
+#endif