Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/CodeGen/DwarfStringPoolEntry.h b/linux-x64/clang/include/llvm/CodeGen/DwarfStringPoolEntry.h
new file mode 100644
index 0000000..e6c0483
--- /dev/null
+++ b/linux-x64/clang/include/llvm/CodeGen/DwarfStringPoolEntry.h
@@ -0,0 +1,53 @@
+//===- llvm/CodeGen/DwarfStringPoolEntry.h - String pool entry --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
+#define LLVM_CODEGEN_DWARFSTRINGPOOLENTRY_H
+
+#include "llvm/ADT/StringMap.h"
+
+namespace llvm {
+
+class MCSymbol;
+
+/// Data for a string pool entry.
+struct DwarfStringPoolEntry {
+  MCSymbol *Symbol;
+  unsigned Offset;
+  unsigned Index;
+};
+
+/// String pool entry reference.
+struct DwarfStringPoolEntryRef {
+  const StringMapEntry<DwarfStringPoolEntry> *I = nullptr;
+
+public:
+  DwarfStringPoolEntryRef() = default;
+  explicit DwarfStringPoolEntryRef(
+      const StringMapEntry<DwarfStringPoolEntry> &I)
+      : I(&I) {}
+
+  explicit operator bool() const { return I; }
+  MCSymbol *getSymbol() const {
+    assert(I->second.Symbol && "No symbol available!");
+    return I->second.Symbol;
+  }
+  unsigned getOffset() const { return I->second.Offset; }
+  unsigned getIndex() const { return I->second.Index; }
+  StringRef getString() const { return I->first(); }
+  /// Return the entire string pool entry for convenience.
+  DwarfStringPoolEntry getEntry() const { return I->getValue(); }
+
+  bool operator==(const DwarfStringPoolEntryRef &X) const { return I == X.I; }
+  bool operator!=(const DwarfStringPoolEntryRef &X) const { return I != X.I; }
+};
+
+} // end namespace llvm
+
+#endif