Update clang to r339409b.

Change-Id: Ied8a188bb072c40035320acedc86164b66d920af
diff --git a/linux-x64/clang/include/llvm/CodeGen/MachineScheduler.h b/linux-x64/clang/include/llvm/CodeGen/MachineScheduler.h
index 85ffa4e..6003b1b 100644
--- a/linux-x64/clang/include/llvm/CodeGen/MachineScheduler.h
+++ b/linux-x64/clang/include/llvm/CodeGen/MachineScheduler.h
@@ -466,6 +466,9 @@
   PressureDiff &getPressureDiff(const SUnit *SU) {
     return SUPressureDiffs[SU->NodeNum];
   }
+  const PressureDiff &getPressureDiff(const SUnit *SU) const {
+    return SUPressureDiffs[SU->NodeNum];
+  }
 
   /// Compute a DFSResult after DAG building is complete, and before any
   /// queue comparisons.
@@ -491,6 +494,8 @@
   /// Compute the cyclic critical path through the DAG.
   unsigned computeCyclicCriticalPath();
 
+  void dump() const override;
+
 protected:
   // Top-Level entry points for the schedule() driver...
 
@@ -895,6 +900,10 @@
 #ifndef NDEBUG
   void traceCandidate(const SchedCandidate &Cand);
 #endif
+
+private:
+  bool shouldReduceLatency(const CandPolicy &Policy, SchedBoundary &CurrZone,
+                           bool ComputeRemLatency, unsigned &RemLatency) const;
 };
 
 // Utility functions used by heuristics in tryCandidate().