Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/include/llvm/CodeGen/MachineBlockFrequencyInfo.h b/linux-x64/clang/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
new file mode 100644
index 0000000..5b4b99c
--- /dev/null
+++ b/linux-x64/clang/include/llvm/CodeGen/MachineBlockFrequencyInfo.h
@@ -0,0 +1,85 @@
+//===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Loops should be simplified before this analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
+#define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
+
+#include "llvm/ADT/Optional.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Support/BlockFrequency.h"
+#include <cstdint>
+#include <memory>
+
+namespace llvm {
+
+template <class BlockT> class BlockFrequencyInfoImpl;
+class MachineBasicBlock;
+class MachineBranchProbabilityInfo;
+class MachineFunction;
+class MachineLoopInfo;
+class raw_ostream;
+
+/// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation
+/// to estimate machine basic block frequencies.
+class MachineBlockFrequencyInfo : public MachineFunctionPass {
+  using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>;
+  std::unique_ptr<ImplType> MBFI;
+
+public:
+  static char ID;
+
+  MachineBlockFrequencyInfo();
+  ~MachineBlockFrequencyInfo() override;
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+  bool runOnMachineFunction(MachineFunction &F) override;
+
+  /// calculate - compute block frequency info for the given function.
+  void calculate(const MachineFunction &F,
+                 const MachineBranchProbabilityInfo &MBPI,
+                 const MachineLoopInfo &MLI);
+
+  void releaseMemory() override;
+
+  /// getblockFreq - Return block frequency. Return 0 if we don't have the
+  /// information. Please note that initial frequency is equal to 1024. It means
+  /// that we should not rely on the value itself, but only on the comparison to
+  /// the other block frequencies. We do this to avoid using of floating points.
+  ///
+  BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
+
+  Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
+  Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
+
+  bool isIrrLoopHeader(const MachineBasicBlock *MBB);
+
+  const MachineFunction *getFunction() const;
+  const MachineBranchProbabilityInfo *getMBPI() const;
+  void view(const Twine &Name, bool isSimple = true) const;
+
+  // Print the block frequency Freq to OS using the current functions entry
+  // frequency to convert freq into a relative decimal form.
+  raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
+
+  // Convenience method that attempts to look up the frequency associated with
+  // BB and print it to OS.
+  raw_ostream &printBlockFreq(raw_ostream &OS,
+                              const MachineBasicBlock *MBB) const;
+
+  uint64_t getEntryFreq() const;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H